Category Archives: Quantum Physics

Bridging quantum and classical physics with nanoparticles – Earth.com

In the ongoing quest to delineate the boundaries between classical and quantum physics, new research has emerged that offers insights into this fundamental scientific challenge.

Published today, this study showcases a pioneering platform with the potential to significantly advance our understanding of where the quantum realm ends and the classical world begins.

Quantum physics, the domain governing the behavior of particles at the minutest scales, introduces phenomena like quantum entanglement, which defies classical physics explanations.

Entanglement illustrates how particles can become so deeply connected that their properties are interdependent, regardless of the distance separating them.

Understanding these quantum mechanics not only fills existing knowledge gaps but also provides a more nuanced comprehension of reality. However, due to the diminutive scale of quantum systems, observing and studying these phenomena poses significant challenges.

Historically, quantum phenomena have been observed in progressively larger entities, ranging from electrons to complex molecules. Yet, the ambition to observe these phenomena in even larger objects introduces new challenges.

Levitated optomechanics, a field focusing on controlling high-mass objects at the micron scale in a vacuum, strives to observe quantum behaviors in substantially larger objects.

The difficulty lies in preserving the quantum characteristics like entanglement, which tend to diminish as objects increase in mass and size, giving way to classical behavior.

A team of researchers led by Dr. Jayadev Vijayan from The University of Manchester, in collaboration with scientists from ETH Zurich and theorists from the University of Innsbruck, has made a significant breakthrough in this area.

Their experiment, conducted at ETH Zurich and detailed in Nature Physics, introduces a novel method to preserve quantum features amidst environmental noise.

To observe quantum phenomena at larger scales and shed light on the classical-quantum transition, quantum features need to be preserved in the presence of noise from the environment. As you can imagine, there are two ways to do this- one is to suppress the noise, and the second is to boost the quantum features, Dr. Vijayan explains.

Our research demonstrates a way to tackle the challenge by taking the second approach. We show that the interactions needed for entanglement between two optically trapped 0.1-micron-sized glass particles can be amplified by several orders of magnitude to overcome losses to the environment, he continued.

The experiment utilized two highly reflective mirrors to create an optical cavity, increasing the likelihood of photon interactions between the particles.

The strength of these optical interactions, mediated by the cavity, remains constant regardless of the distance, enabling us to couple micron-scale particles over several millimeters, adds Johannes Piotrowski from ETH Zurich.

This advancement not only propels us closer to understanding the quantum-classical transition but also opens the door to practical applications, especially in sensor technology. Dr. Carlos Gonzalez-Ballestero from the Technical University of Vienna highlights the implications.

The key strength of levitated mechanical sensors is their high mass relative to other quantum systems using sensing. The high mass makes them well-suited for detecting gravitational forces and accelerations, resulting in better sensitivity, Gonzalez-Ballestero elaborated.

As such, quantum sensors can be used in many different applications in various fields, such as monitoring polar ice for climate research and measuring accelerations for navigation purposes, he concluded.

Piotrowski reflects on the excitement of pushing the boundaries of this nascent platform towards the quantum regime. The team plans to integrate these capabilities with established quantum cooling techniques, aiming to validate quantum entanglement further.

Successful entanglement of levitated particles could dramatically bridge the gap between quantum mechanics and classical physics, merging these two realms closer than ever before.

In summary, the recent breakthrough in quantum physics research, led by Dr. Jayadev Vijayan and his international team, marks a significant advancement in bridging the gap between the quantum and classical worlds.

By amplifying the interactions necessary for entanglement in micron-scale particles, this study enhances our understanding of quantum phenomena at larger scales and paves the way for innovative applications in sensor technology.

As the team moves forward to integrate these findings with quantum cooling techniques, the potential for validating quantum entanglement in levitated particles holds the promise of revolutionizing our approach to physics, offering new insights into the fundamental nature of reality and opening up a myriad of practical applications across various fields.

The full study was published in the journal Nature Physics.

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Bridging quantum and classical physics with nanoparticles - Earth.com

Quantum Revolution: Redefining Physics With Fractional Charges – SciTechDaily

Electrons whizzing through the kagome metal Fe3Sn2 are influenced by the proximity of a flat band (shown by the reflection of the top ball on a flat surface). This causes the electronic charge to be fractionalized, or split (shown here by the appearance of the lower ball). Researchers have now observed this effect spectroscopically. Credit: Paul Scherrer Institute / Sandy Ekahana

Quantum mechanics tells us that the fundamental unit of charge is unbreakable but exceptions exist.

A research team led by the Paul Scherrer Institute has spectroscopically observed fractionalization of electronic charge in an iron-based metallic ferromagnet. Experimental observation of the phenomenon is not only of fundamental importance. Since it appears in an alloy of common metals at accessible temperatures, it holds potential for future exploitation in electronic devices. The discovery is published in the journal Nature.

Basic quantum mechanics tells us that the fundamental unit of charge is unbreakable: the electron charge is quantized. Yet, we have come to understand that exceptions exist. In some situations, electrons arrange themselves collectively as if they were split into independent entities, each possessing a fraction of the charge.

The fact that charge can be fractionalised is not new: it has been observed experimentally since the late 1980s with the Fractional Quantum Hall Effect. In this, the conductance of a system in which electrons are confined to a two-dimensional plane is observed to be quantized in fractional rather than integer units of charge.

The Hall Effect provides an indirect measure of charge fractionalization, through a macroscopic manifestation of the phenomenon: the voltage. As such, it does not reveal the microscopic behavior the dynamics of fractional charges. The research team, a collaboration between institutions in Switzerland and China, has now revealed such dynamics via spectroscopy of electrons emitted from a ferromagnet when illuminated by a laser.

To fractionalise charges, you need to take electrons to a strange place where they stop following normal rules. In conventional metals, electrons typically move through the material, generally ignoring each other apart from the occasional bump. They possess a range of different energies. The energy levels in which they lie are described as dispersive bands, where the kinetic energy of the electrons depends on their momenta.

In some materials, certain extreme conditions can push electrons to start interacting and behaving collectively. Flat bands are regions in the electronic structure of a material where the electrons all lie in the same energy state, i.e., where they have nearly infinite effective masses. Here, electrons are too heavy to escape each other and strong interactions between electrons reign. Rare and sought after, flat bands can lead to phenomena including exotic forms of magnetism or topological phases such as fractional quantum Hall states.

To observe the Fractional Quantum Hall Effect, strong magnetic fields and very low temperatures are applied, which suppress the kinetic energy of electrons and promote strong interactions and collective behavior.

The research team could achieve this in a different way, without application of a strong magnetic field: by creating a lattice structure that reduces electron kinetic energies and allows them to interact. Such a lattice is the Japanese woven bamboo kagome mat, which characterizes atomic layers in a surprisingly large number of chemical compounds. They made their discovery in Fe3Sn2, a compound consisting only of the common elements iron (Fe) and tin (Sn) assembled according to the kagome pattern of corner sharing triangles.

Laser ARPES Allows a Closer Look

The researchers did not set out to observe charge fractionalization in kagome Fe3Sn2. Instead, they were simply interested in verifying whether flat bands existed as predicted for this ferromagnetic material.

Using laser angle resolved photoemission spectroscopy (laser ARPES) at the University of Geneva with a very small beam diameter, they could probe the local electronic structure of the material at an unprecedented resolution.

The band structure in kagome Fe3Sn2 is different depending on which ferromagnetic domain you are probing. We were interested to see whether, using the micro-focused beam, we could detect inhomogeneities in the electronic structure correlated to domains that had been previously missed, says Sandy Ekahana, postdoctoral fellow in the Quantum Technology group at PSI and first author of the study.

Electron Pockets and Colliding Bands

Focusing on certain crystal domains, the team identified a feature known as electron pockets. These are regions in the momentum space of a materials electronic band structure where the energy of electrons is at a minimum, effectively forming pockets where electrons hang out. Here, the electrons behave as collective excitations, or quasiparticles.

On examining these closely, the researchers detected strange features in the electronic band structure that were not fully explained by theory. The laser ARPES measurements revealed a dispersive band, which did not match with density functional theory (DFT) calculations one of the most established methods to study electron interactions and behaviors in materials. It quite often happens that DFT doesnt quite match. But from an experimental point of view alone, this band was extremely peculiar. It was extremely sharp, but then it suddenly cut off. This is not normal usually bands are continuous, explains Yona Soh, scientist at PSI and corresponding author of the study.

The researchers realized that they were observing a dispersive band interacting with a flat band, predicted to exist by colleagues from EPFL. The observation of a flat band interacting with a dispersive band is itself of deep interest: It is believed that the interaction between flat and dispersive bands allows new phases of matter to emerge, such as marginal metals where electrons do not travel much further than their quantum wavelength and peculiar superconductors.

There has been a lot of theoretical discussion about the interaction between flat and dispersive bands, but this is the first time that a new band caused by this interaction has been discovered spectroscopically, says Soh.

Weird Electron Behavior Gets Even Weirder: Fractionalization of Charge

The consequences of this observation are even more profound. Where the two bands meet, they hybridize to make a new band. The original dispersive band is occupied. The flat band is unoccupied as it lies above the Fermi level a concept that describes the cutoff between occupied and unoccupied energy levels. When the new band is created, the charge is split between the original dispersive band and the new band. This means that each band contains only a fraction of the charge.

In this way, the measurements by Ekahana and colleagues provide direct spectroscopic observation of charge fractionalization.

Achieving and observing states in which charge is fractionalised is exciting not only from the perspective of fundamental research, says Gabriel Aeppli, head of the photon science division at PSI and professor at EPFL and ETH Zurich, who proposed the study. We observe this in an alloy of common metals at low, but still relatively accessible temperatures. This makes it worthwhile considering whether there are electronic devices that might exploit fractionalization.

Reference: Anomalous electrons in a metallic kagome ferromagnet by Sandy Adhitia Ekahana, Y. Soh, Anna Tamai, Daniel Goslbez-Martnez, Mengyu Yao, Andrew Hunter, Wenhui Fan, Yihao Wang, Junbo Li, Armin Kleibert, C. A. F. Vaz, Junzhang Ma, Hyungjun Lee, Yimin Xiong, Oleg V. Yazyev, Felix Baumberger, Ming Shi and G. Aeppli, 6 March 2024,Nature. DOI: 10.1038/s41586-024-07085-w

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Quantum Revolution: Redefining Physics With Fractional Charges - SciTechDaily

Carnegie Mellon researchers develop new machine learning method for modeling of chemical reactions – EurekAlert

video:

A simulation demonstrates the reactions that the ANI-1xnr can produce. ANI-1xnr can simulate reactive processes for organic materials, such as as carbon, using less computing power and time than traditional simulation models. The video is courtesy of Carnegie Mellon University's Shuhao Zhang, first author on Exploring the Frontiers of Condensed-Phase Chemistry with a General Reactive Machine Learning Potential.

Credit: courtesy of Shuhao Zhang, Carnegie Mellon University

Researchers from Carnegie Mellon University and Los Alamos National Laboratory have used machine learning to create a model that can simulate reactive processes in a diverse set of organic materials and conditions.

"It's a tool that can be used to investigate more reactions in this field," said Shuhao Zhang, a graduate student in Carnegie Mellon University's Department of Chemistry. "We can offer a full simulation of the reaction mechanisms."

Zhang is the first author on the paper that explains the creation and results of this new machine learning model, "Exploring the Frontiers of Chemistry with a General Reactive Machine Learning Potential," which will be published in Nature Chemistry on March 7.

Though researchers have simulated reactions before, previous methods had multiple problems. Reactive force field models are relatively common, but they usually require training for specific reaction types. Traditional models which use quantum mechanics, where chemical reactions are simulated based on underlying physics, can be applied to any materials and molecules, but these models require supercomputers to be used.

This new general machine learning interatomic potential (ANI-1xnr), can perform simulations for arbitrary materials containing the elements carbon, hydrogen, nitrogen and oxygen and requires significantly less computing power and time than traditional quantum mechanics models. According to Olexandr Isayev, associate professor of chemistry at Carnegie Mellon and head of the lab where the model was developed, this breakthrough is due to developments in machine learning.

"Machine learning is emerging as a powerful approach to construct various forms of transferable atomistic potentials utilizing regression algorithms. The overall goal of this project is to develop a machine learning method capable of predicting reaction energetics and rates for chemical processes with high accuracy, but with a very low computational cost," Isayev said. "We have shown that those machine learning models can be trained at high levels of quantum mechanics theory and can successfully predict energies and forces with quantum mechanics accuracy and an increase in speed of as much as 6-7 orders of magnitude. This is a new paradigm in reactive simulations."

Researchers tested ANI-1xnr on different chemical problems, including comparing biofuel additives and tracking methane combustion. They even recreated the Miller experiment, a famous chemical experiment meant to demonstrate how life originated on Earth. Using this experiment, they found that the ANI-1xnr model produced accurate results in condensed phase systems.

Zhang said that the model could potentially be used for other areas in chemistry with further training.

"We found out it can be potentially used to simulate biochemical processes like enzymatic reactions," Zhang said. "We didn't design it to be used in such a way, but after modification it may be used for that purpose.

In the future, the team plans to refine ANI-1xnr and allow it to work with more elements and in more chemical areas, and they will try to increase the scale of the reactions it can process. This could allow it to be used in multiple fields where designing new chemical reactions could be relevant, such as drug discovery.

Zhang and Isayev were joined by Magorzata Z. Mako, Ryan B. Jadrich, Elfi Kraka, Kipton Barros, Benjamin T. Nebgen, Sergei Tretiak, Nicholas Lubbers, Richard A. Messerly and Justin S. Smith. The project received funding from the Office of Naval Research (ONR) through Energetic Materials Program (MURI grant number N00014-21-1-2476) to Isayev.

Computational simulation/modeling

Not applicable

Exploring the Frontiers of Chemistry with a General Reactive Machine Learning Potential

7-Mar-2024

The authors declare no competing financial interests.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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Carnegie Mellon researchers develop new machine learning method for modeling of chemical reactions - EurekAlert

Understanding Cavity-Mediated Interactions – AZoQuantum

Mar 4 2024Reviewed by Lexie Corner

The inquiry into the precise location of the demarcation line separating classical and quantum physics has been a longstanding focus of contemporary scientific investigation.

In a recent publication, researchers introduce an innovative framework that could aid in resolving this fundamental question.

The principles of quantum physics dictate the actions of particles on a tiny scale, resulting in occurrences like quantum entanglement, in which the characteristics of entangled particles are intricately connected in a manner that defies explanation by classical physics.

Research in quantum physics improvesthe understanding of physics and provides a more comprehensive view of reality. However, the minuscule scales at which quantum systems function pose challenges in their observation and study.

Since the turn of the 20th century, scientists have been able to study quantum phenomena in larger objectsfrom subatomic particles like electrons to molecules composedof hundreds of atoms.

Recently, the area of levitated optomechanics has been focusing on manipulating high-mass micron-scale objects in a vacuum to explore the boundaries of quantum phenomena. The goal is to investigate the validity of quantum principles in objects significantly heavier than atoms and molecules.

Nevertheless, as the mass and size of an object increase, the interactions responsible for intricate quantum characteristics, like entanglement, are compromised by environmental factors, leading to the classical behavior that is commonly observed.

However, a new method to address this issue has been developed by the team co-led by Dr. Jayadev Vijayan, who heads the Quantum Engineering Lab at The University of Manchester. Collaborating with scientists from ETH Zurich and theorists from the University of Innsbruck, the team conducted an experiment at ETH Zurich, which was subsequently published in the journal Nature Physics.

To observe quantum phenomena at larger scales and shed light on the classical-quantum transition, quantum features need to be preserved in the presence of noise from the environment. As you can imagine, there are two ways to do this- one is to suppress the noise, and the second is to boost the quantum features. Our research demonstrates a way to tackle the challenge by taking the second approach. We show that the interactions needed for entanglement between two optically trapped 0.1-micron-sized glass particles can be amplified by several orders of magnitude to overcome losses to the environment.

Dr. Jayadev Vijayan, Head, Quantum Engineering Lab, The University of Manchester

The researchers positioned the particles amidst two extremely reflective mirrors, creating an optical cavity. Consequently, the photons emitted by each particle reflect back and forth between the mirrors numerous times before exiting the cavity, resulting in a notably increased likelihood of interacting with the other particle.

Remarkably, because the optical interactions are mediated by the cavity, its strength does not decay with distance meaning we could couple micron-scale particles over several mm.

Johannes Piotrowski, Study Co-Lead, ETH Zurich

The researchers positioned the particles amidst two extremely reflective mirrors, creating an optical cavity. Consequently, the photons emitted by each particle reflect back and forth between the mirrors numerous times before exiting the cavity, resulting in a notably increased likelihood of interacting with the other particle.

The results indicate a major step forward in comprehending basic physics and showing potential for real-world use, especially in sensor technology for environmental monitoring and offline navigation.

The key strength of levitated mechanical sensors is their high mass relative to other quantum systems using sensing. The high mass makes them well-suited for detecting gravitational forces and accelerations, resulting in better sensitivity. As such, quantum sensors can be used in various applications in various fields, such as monitoring polar ice for climate research and measuring accelerations for navigation purposes.

Dr. Carlos Gonzalez-Ballestero, Assistant Professor, Technical University of Vienna

Piotrowski added, It is exciting to work on this relatively new platform and test how far we can push it into the quantum regime.

The researchers will now integrate the new capabilities with established quantum cooling methods to progress toward verifying quantum entanglement. Successfully achieving entanglement of levitated nano- and micro-particles can bridge the divide between the quantum realm and everyday classical mechanics.

Dr. Jayadev Vijayans group at the Photon Science Institute and the Department of Electrical and Electronic Engineering at The University of Manchester will continuetheir work in levitated optomechanics, using multi-nanoparticle interactions for quantum sensing applications.

Vijayan, J., et al., (2024) Cavity-mediated long-range interactions in levitated optomechanics. Nature Physics. doi.org/10.1038/s41567-024-02405-3.

Source: https://www.manchester.ac.uk/

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Understanding Cavity-Mediated Interactions - AZoQuantum

Longer coherence: How the quantum computing industry is maturing – DatacenterDynamics

Quantum computing theory dates back to the 1980s, but it's really only in the last five to ten years or so that weve seen it advance enough to the point it could realistically become a commercial enterprise.

Most quantum computing companies have been academic-led science ventures; companies founded by PhDs leading teams of PhDs. But, as the industry matures and companies look towards a future of manufacturing and operating quantum computers at a production-scale, the employee demographics are changing.

While R&D will always play a core part of every technology company, making quantum computers viable out in the real world means these startups are thinking about how to build, maintain, and operate SLA-bound systems in production environments.

This new phase in the industry requires companies to change mindset, technology, and staff.

Plus rebuilding Ukraine, Cologix's CEO, and more

20 Dec 2023

At quantum computing firm Atom Computing, around 40 of the companys 70 employees have PhDs, many joining straight out of academia. This kind of academic-heavy employee demographic is commonplace across the quantum industry.

I'd venture that over half of our company doesn't have experience working at a company previously, says Rob Hays, CEO of Atom. So theres an interesting bridge between the academic culture versus the Silicon Valley tech startup; those are two different worlds and trying to bridge people from one world to the other is challenging. And it's something you have to focus and work on openly and actively.

Maturing from small startups into large companies with demanding customers and shareholders is a well-trodden path for hundreds of technology companies in Silicon Valley and across the world.

And quantum computers are getting there: the likes of IonQ, Rigetti, and D-Wave are already listed in the Nasdaq and New York Stock Exchange although the latter two companies have had to deal at various times with the prospect of being de-listed due to low stock prices.

Most of the quantum companies DCD spoke to for this piece are undergoing a transition from pure R&D mode to a more operational and engineering phase.

When I first joined four years ago, the company was entirely PhDs, says Peter Chapman, IonQ CEO. We're now in the middle of a cultural change from an academic organization and moving to an engineering organization. We've stopped hiring PhDs; most of the people we're hiring nowadays are software, mechanical, and hardware engineers. And the next phase is to a customer-focused product company.

Chapman points to the hirings of the likes of Pat Tan and Dean Kassmann previously at Amazons hardware-focused Lab126 and rocket firm Blue Origin, respectively as evidence of the company moving to a more product- and engineering-focused workforce.

2023 also saw Chris Monroe, IonQ co-founder and chief scientist, leave the company to return to academia at North Carolinas Duke University.

During the earnings call announcing Monroes departure, Chapman said: Chris would be the first one to tell you that the physics behind what IonQ is doing is now solved. It's [now] largely an engineering problem.

Atoms Hays notes a lot of the engineering work that the company is doing to get ready for cloud services and applications is software-based, meaning the company is looking for software engineers.

We are mostly looking for people that have worked at cloud service providers or large software companies and have an interest in either learning or already some foundational knowledge of the underlying physics and science, he says. But we're kind of fortunate that those people self-select and find us. We have a pretty high number of software engineers who have physics undergrads and an extreme interest in quantum mechanics, even though by trade and experience they're software engineers.

On-premise quantum computers are currently rarities largely reserved for national computing labs and academic institutions. Most quantum processing unit (QPU) providers offer access to their systems via their own web portals and through public cloud providers.

But todays systems are rarely expected (or contracted) to run with the five-9s resiliency and redundancy we might expect from tried and tested silicon hardware.

Right now, quantum systems are more like supercomputers and they're managed with a queue; they're probably not online 24 hours, users enter jobs into a queue and get answers back as the queue executes, says Atoms Hays.

We are approaching how we get closer to 24/7 and how we build in redundancy and failover so that if one system has come offline for maintenance, there's another one available at all times. How do we build a system architecturally and engineering-wise, where we can do hot swaps or upgrades or changes with minimal downtime as possible?

Other providers are going through similar teething phases of how to make their systems which are currently sensitive, temperamental, and complicated enterprise-ready for the data centers of the world.

I already have a firm SLA with the cloud guys around the amount of time that we do jobs on a daily basis, and the timeframes to be able to do that, says Chapman. We are moving that SLA to 24/7 and being able to do that without having an operator present. It's not perfect, but its getting better. In three or four years from now, you'll only need an on-call when a component dies.

Rigetti CTO David Rivas says his company is also working towards higher uptimes.

The systems themselves are becoming more and more lights out every quarter, he says, as we outfit them for that kind of remote operation and ensure that the production facilities can be outfitted for that kind of operation.

Rigetti

Manufacturing and repair of these systems is also maturing, since the first PhD-built generations of quantum computers. These will never be mass-produced, but the industry needs to move away from one-off artisanal machines to a more production line-like approach.

A lot of the hardware does get built with the assistance of electronics engineers, mechanical engineers, says Atoms Hays, but much is still built by experimental physicists.

IonQs Chapman adds: In our first-generation systems, you needed a physicist with a screwdriver to tune the machine to be able to run your application. But every generation of hardware puts more under software control.

Everywhere a screwdriver could be turned, there's now a stepper motor under software control, and the operating system is now doing the tuning.

Simon Phillips, CTO of the UKs Oxford Quantum Circuits, says OQC is focused on how it hires staff and works with partners to roll out QPUs into colocation data centers.

And the first part of that starts with if we put 10 QPUs in 10 locations around the world, how do we do that without having an army of 100 quantum engineers on each installation?

And the first part of that starts with having a separate deployment team and a site reliability engineering team that can then run the SLA on that machine.

He adds: Not all problems are quantum problems. It can't just be quantum engineers; it's not scalable if it's the same people doing everything.

It's about training and understanding where the first and second lines of support sit, having a cascading system, and utilizing any smart hands so we can train people who already exist in data centers.

IonQ

While the quantum startups are undergoing their own maturing process, their suppliers are also being forced to learn about the needs of commercial operators and what it means to deploy in a production data center.

For years, the supply chain including for the dilution refrigerators that keep many quantum computers supercooled has dealt with largely self-reliant academic customers in lab spaces.

Richard Moulds, general manager of Amazon Braket at AWS, told DCD the dilution refrigerator market is a cottage industry with few suppliers.

One of the main fridge suppliers is Oxford Instruments, an Oxford University spin-out from the late 1950s that released the first commercial dilution unit back in 1966. The other large incumbent, Blufors, was spun out of what is now the Low Temperature Laboratory at Aalto University in Finland 15 years ago.

Prior to the quantum computing rush, the biggest change in recent years was the introduction of pulse tube technology. Instead of a cryostat inserted into a bath of liquid helium4, quantum computers could now use a closed loop system (aka a dry fridge/cryostat).

This meant the systems could become smaller, more efficient, more software-controlled - and more user-friendly.

With the wet dilution fridge (or wet cryostat), you need two-floor rooms for ceiling height. You need technicians to top up helium and run liquefiers, you need to buy helium to keep topping up, says Harriet van der Vliet, product segment manager, quantum technologies, Oxford Instruments.

It was quite a manual process and it would take maybe a week just to pre-cool and that would not even be getting to base temperature.

For years, the fridges were the preserve of academics doing materials science; they were more likely to win a Nobel prize than be part of a computing contract.

Historically, it's been a lab product. Our customers were ultra-low temperature (ULT) experts; if anything went wrong, they would fix it themselves, says van der Vliet. Now our customers have moved from being simply academics to being commercial players who need user-friendly systems that are push button.

While the company declined to break out numbers, Oxford said it has seen a noticeable change in the customer demographic towards commercial quantum computing customers in recent years, but also a change in buying trends. QPU companies are more likely to buy multiple fridges at once, rather than a single unit every few years for an academic research lab.

The commercial part is growing for sure, adds David Gunnarsson, CTO at Blufors. The company has expanded factory capacity to almost double production capabilities to meet growing demand.

There have been more and more attempts to create revenue on quantum computing technology. They are buying our systems to actually deploy or have an application that they think they can create money from. We welcome discussion with data centers so they can understand our technology from the cryogenics perspective.

And while the industry is working towards minimizing form factors as much as possible, for the foreseeable future the industry has settled on essentially brute force supercooling with bigger fridges. Both companies have released new dilution fridges designed for quantum computers.

Smaller fridges (and lower qubit-count) systems may be able to fit into racks, but most larger qubit-count supercooled systems require a much larger footprint than traditional racks. Blufors largest Kide system can cool around 1,000 qubits: the system is just under three meters in height and 2.5 meters in diameter, and the floor beneath it needs to be able to take about 7,000 kilograms of weight.

It has changed the way we do our product, says Gunnarsson. They were lab tools before; uptime wasnt discussed much before. Now we are making a lot of changes to our product line to ensure that you can be more certain about what the uptime of your system will be.

Part of the uptime challenge suppliers face around fridges an area where Gunnarsson notes there is still something of a mismatch is in the warm-up/cool-down cycle of the machines.

While previously the wet bath systems could take a week to get to the required temperatures, the new dry systems might only take a day or two each way. That is important, because cooling down and warming up cycles are effectively downtime; a dirty word when talking about service availability.

The speed with which you can get to temperature is almost as important as the size of the chip that you can actually chill, says AWS Moulds. Today, if you want to change the device's physical silicon, you have got to warm this device up and then chill it back down again, that's a four-day cycle. That's a problem; it means machines are offline for a long time for relatively minor changes.

While this might not be an issue for in-operation machines Rigetti CTO Rivas says its machines can be in service for months at a time, while Oxford Instruments says an OQC system was in operation non-stop for more than a year the long warm-up/cool-down cycle is a barrier to rapid testing.

From a production perspective, the systems remain cold for a relatively long time, says Rivas. But we're constantly running chips through test systems as we innovate and grow capacity, and 48 hours to cool a chip down is a long time in an overall development cycle.

Oxford Instruments and Blufors might be the incumbents, but there are a growing number of new players entering the fridge space, some specifically focusing on quantum computing.

The market has grown for dilution fridges, so there are lots more startups in the space as well making different cooling systems, says van der Vliet. There are many more players, but the market is growing.

I think it's really healthy that there's loads of players in the field, particularly new players who are doing things a little bit differently to how we've always done it.

The incumbents are well-placed to continue their lead in the market, but QPU operators are hopeful that competition will result in better products.

There will be genuine intellectual property that will emerge in this area and you'll definitely start to see custom designs and proprietary systems that can maintain temperature in the face of increasing power.

Atoms Hays notes that, for laser-based quantum systems, the lasers themselves are probably the largest constraint in the supply chain. Like the dilution fridges, these are still largely scientific technologies made by a handful of suppliers.

We need relatively high-powered lasers that need to be very quiet and very precise," he says. Ours are off the shelf, but they're semi-custom and manufacturer builds to order. That means that there's long lead times; in some cases up to a year.

He adds that many of the photonic integrated circuits are still relatively small - the size of nickels and dimes - but hopes they can shrink down to semiconductor size in future to help reduce the footprint

For now, the quantum industry is still enjoying what might be the autumn of its happy-go-lucky academic days. The next phase may well lead to quantum supremacy and a new phase in high-performance computing, but it will likely lead to a less open industry.

I think its nice that the industry is still sort of in that mode, says AWS Moulds. The industry is still taking a relatively open approach to the development. We're not yet in the mode of everybody working in their secret bunkers, building secret machines. But history shows that once there's a clear opportunity, there's a risk of the shutters coming down, and it becoming a more cut-throat industry.

In the end, that's good for customers; it drives down costs and drives up reliability and performance. But it might feel that might feel a little bit brutal for some of the academics that are in the industry now.

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Longer coherence: How the quantum computing industry is maturing - DatacenterDynamics

Quantum Leap in Ultrafast Electronics Secured by Graphene’s Atomic Armor – SciTechDaily

Schematic representation showing how a graphene layer protects against water. The electrical current flowing along the edge of the topological insulator indenene remains completely unaffected by external influences. Credit: Jrg Bandmann, pixelwg

Researchers have developed a groundbreaking protective coating for indenene, a quantum material promising for ultrafast electronics, enabling its use in air without oxidation. This innovation could revolutionize the future of atomic layer electronics.

The race to create increasingly faster and more powerful computer chips continues as transistors, their fundamental components, shrink to ever smaller and more compact sizes. In a few years, these transistors will measure just a few atoms across by which point, the miniaturization of the silicon technology currently used will have reached its physical limits. Consequently, the quest for alternative materials with entirely new properties is crucial for future technological advancements.

Back in 2021, scientists from the Cluster of Excellence ct.qmat Complexity and Topology in Quantum Matter at the universities JMU Wrzburg and TU Dresden made a significant discovery: topological quantum materials such as indenene, which hold great promise for ultrafast, energy-efficient electronics. The resulting, extremely thin quantum semiconductors are composed of a single atom layer in indenenes case, indium atoms and act as topological insulators, conducting electricity virtually without resistance along their edges.

Producing such a single atomic layer requires sophisticated vacuum equipment and a specific substrate material. To utilize this two-dimensional material in electronic components, it would need to be removed from the vacuum environment. However, exposure to air, even briefly, leads to oxidation, destroying its revolutionary properties and rendering it useless, explains experimental physicist Professor Ralph Claessen, ct.qmats Wrzburg spokesperson.

The ct.qmat Wrzburg team has now managed to solve this problem. Their results have been published in the journal Nature Communications.

Amalgamation of experimental images. At the top, a scanning tunneling microscopy image displays the graphenes honeycomb lattice (the protective layer). In the center, electron microscopy shows a top view of the material indenene as a triangular lattice. Below it is a side view of the silicon carbide substrate. It can be seen that both the indenene and the graphene consist of a single atomic layer. Credit: Jonas Erhardt/Christoph Mder)

We dedicated two years to finding a method to protect the sensitive indenene layer from environmental elements using a protective coating. The challenge was ensuring that this coating did not interact with the indenene layer, explains Cedric Schmitt, one of Claessens doctoral students involved in the project. This interaction is problematic because when different types of atoms from the protective layer and the semiconductor, for instance meet, they react chemically at the atomic level, changing the material. This isnt a problem with conventional silicon chips, which comprise multiple atomic layers, leaving sufficient layers unaffected and hence still functional.

A semiconductor material consisting of a single atomic layer such as indenene would normally be compromised by a protective film. This posed a seemingly insurmountable challenge that piqued our research curiosity, says Claessen. The search for a viable protective layer led them to explore van der Waals materials, named after the Dutch physicist Johannes Diderik van der Waals (18371923). Claessen explains: These two-dimensional van der Waals atomic layers are characterized by strong internal bonds between their atoms, while only weakly bonding to the substrate. This concept is akin to how pencil lead made of graphite a form of carbon with atoms arranged in honeycomb layers writes on paper. The layers of graphene can be easily separated. We aimed to replicate this characteristic.

Using sophisticated ultrahigh vacuum equipment, the Wrzburg team experimented with heating silicon carbide (SiC) as a substrate for indenene, exploring the conditions needed to form graphene from it. Silicon carbide consists of silicon and carbon atoms. Heating it causes the carbon atoms to detach from the surface and form graphene, says Schmitt, elucidating the laboratory process. We then vapor-deposited indium atoms, which are immersed between the protective graphene layer and the silicon carbide substrate. This is how the protective layer for our two-dimensional quantum material indenene was formed.

For the first time globally, Claessen and his team at ct.qmats Wrzburg branch successfully crafted a functional protective layer for a two-dimensional quantum semiconductor material without compromising its extraordinary quantum properties. After analyzing the fabrication process, they thoroughly tested the layers protective capabilities against oxidation and corrosion. It works! The sample can even be exposed to water without being affected in any way, says Claessen with delight. The graphene layer acts like an umbrella for our indenene.

This breakthrough paves the way for applications involving highly sensitive semiconductor atomic layers. The manufacture of ultrathin electronic components requires them to be processed in air or other chemical environments. This has been made possible thanks to the discovery of this protective mechanism. The team in Wrzburg is now focused on identifying more van der Waals materials that can serve as protective layers and they already have a few prospects in mind. The snag is that despite graphenes effective protection of atomic monolayers against environmental factors, its electrical conductivity poses a risk of short circuits. The Wrzburg scientists are working on overcoming these challenges and creating the conditions for tomorrows atomic layer electronics.

The Cluster of Excellence ct.qmat Complexity and Topology in Quantum Matter has been jointly run by Julius-Maximilians-Universitt (JMU) Wrzburg and Technische Universitt (TU) Dresden since 2019. Over 300 scientists from more than thirty countries and four continents study topological quantum materials that reveal surprising phenomena under extreme conditions such as ultra-low temperatures, high pressure, or strong magnetic fields. ct.qmat is funded through the German Excellence Strategy of the Federal and State Governments and is the only Cluster of Excellence in Germany to be based in two different federal states.

Reference: Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation by Cedric Schmitt, Jonas Erhardt, Philipp Eck, Matthias Schmitt, Kyungchan Lee, Philipp Keler, Tim Wagner, Merit Spring, Bing Liu, Stefan Enzner, Martin Kamp, Vedran Jovic, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Timur Kim, Cephise Cacho, Tien-Lin Lee, Giorgio Sangiovanni, Simon Moser and Ralph Claessen, 19 February 2024, Nature Communications. DOI: 10.1038/s41467-024-45816-9

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Quantum Leap in Ultrafast Electronics Secured by Graphene's Atomic Armor - SciTechDaily

Why quantum technology may hold the key to alternative energy – Observer Research Foundation

With conventional energy sources like fossil fuels depleting fast, not to mention their adverse effects on the environment, the world has been in desperate need of alternative means to address our ever-growing energy needs. Attempts include solar, wind, geothermal and hydro-energy, nuclear fusion reactors, hydrogen energy and sodium-ion batteries, to name a few. While all these have certainly been laudable efforts, most have faced severe challenges and as a result, have achieved low to moderate success. The search for a viable substitute to fossil fuels goes on, once again putting human ingenuity to the test. The answer may come, however, from the unlikeliest of places, the quantum nature of reality itself.

Having been established more than a century ago, quantum theory remains a subject of much discussion and debate within the physics community itself. This is partly owing to the non-intuitive nature of the subject since it is extremely difficult for us to visualise how the world functions on such a microscopic scale. It turns out that the universe is quite peculiar at the quantum scale, and seems to defy conventional logic. In short, quantum theory is just strange. Consequently, despite being the most successful and accurate theory to date, it is nowhere near complete, and there are fundamental questions which remain unanswered.

With conventional energy sources like fossil fuels depleting fast, not to mention their adverse effects on the environment, the world has been in desperate need of alternative means to address our ever-growing energy needs.

This long pursuit to understand how nature works on a fundamental level led us down an unexpected path, something which we could not have foreseen, and is now begging us to ask an important questionIs it possible to utilise the quantum nature of matter itself to create an alternative source of energy? Ongoing research in the field seems to suggest that the answer to this question is a resounding yes. Recent work on quantum batteries and quantum engines indicates that quantum technology may indeed hold the key to the future of energy generation, and we have barely even scratched the surface.

While they seemed to be a distant reality for the time being, a research group comprising scientists from the University of Tokyo and the Beijing Computational Research Centre has made a recent breakthrough which could make quantum batteries a practical reality sooner than expected. Conventional chemical batteries rely on materials like lithium to store charge. Quantum batteries, on the other hand, use individual particles like photons to store energy.

Solar panels notoriously lose efficiency due to thermal losses, but leveraging ICO could mitigate these losses, leading to significantly enhanced energy output.

The essential idea the group used is a purely quantum phenomenon known as Indefinite Causal Order (ICO) which modifies our usual notion of the flow of time. The macroscopic world follows the rule of causality, if event 1 precedes event 2, the reverse cannot happen. This, however, is not necessarily the case when it comes to the quantum world. ICO implies that event 1 leading to event 2, and event 2 leading to event 1, can take place simultaneously via the principle of superposition. This led to the unexpected result that a lower-power charger could provide higher energies with greater efficiency compared to a higher-power charger using the same apparatus.

The implications of this breakthrough extend far beyond portable devices. ICO's ability to manipulate heat transfer within quantum systems could revolutionise solar energy capture. Solar panels notoriously lose efficiency due to thermal losses, but leveraging ICO could mitigate these losses, leading to significantly enhanced energy output.

Figure 1: Charging quantum batteries in indefinite causal order. In the classical world, if you tried to charge a battery using two chargers, you would have to do so in sequence, limiting the available options to just two possible orders. However, leveraging the novel quantum effect called ICO opens the possibility to charge quantum batteries in a distinctively unconventional way. Here, multiple chargers arranged in different orders can exist simultaneously, forming a quantum superposition. Source: Chen et al (2023).

Though quantum engines are a more ambitious undertaking than batteries, the recent work by researchers at the University of Kaiserslautern, Germany, suggests they may hold massive potential in the future. While conventional engines use the Carnot cycle to convert heat or thermal energy into mechanical work, this particular quantum engine works on the energy differences which arise as a result of the statistical properties of quantum particles.

The bosons pile up in the lowest energy state, while the fermions keep ascending and stacking on top of each other, thereby increasing the energy of the system.

According to quantum mechanics, nature consists of two kinds of particles: bosons and fermions. While any energy state can accommodate an infinitely large number of bosons, it can only hold one fermion at a given point in time, meaning that no two fermions can occupy the same state. This is the foundation of the famous Pauli Exclusion Principle.

Although this effect is not important at room temperature, it becomes increasingly dominant as we cool the particles down to absolute zero temperatures (-273o Celsius or 0 Kelvin). The bosons pile up in the lowest energy state, while the fermions keep ascending and stacking on top of each other, thereby increasing the energy of the system. Therefore, at very low temperatures, fermions possess much more energy than bosons.

Figure 2: Blue balls indicate bosons and red and green balls indicate fermions. Green and red balls correspond to two spin states (spin up and spin down). Bosons pile up at the ground state while fermions keep ascending in energy. Source: S. Will (2011).

In the early 2000s, it was discovered that it is possible toconvert a gas of fermions into bosons and vice-versa using magnetic fields. When this process is performed cyclically, the energy difference between fermions and bosons can in principle be converted into mechanical energy, similar to how a conventional engine works. The main difference here is that instead of using heat, the driving force in quantum engines turns out to be the difference in the fundamental nature of the quantum particles themselves.

While the experiment was a proof-of-concept demonstration, there is no denying the possibilities it presents. While quantum engines seem poised to be a viable source of energy for powering quantum computers and quantum sensors in the future, it is entirely within the realm of possibility that they may be able to power something even bigger down the road.

There have been numerous technological advancements in the field of alternative and renewable energy lately. However, most, if not all of them, are critically dependent on limited resources, which are bound to run out eventually. For instance, nuclear fusion, despite being one of the cleanest sources of energy, is still completely reliant on scarce materials like tritium. The severe shortage in the supply of semiconductors recently had an adverse impact on the manufacture of electric vehicles in 2023, an industry which is already set to contend with a lithium supply crunch in the future. And while green hydrogen seems like an exciting prospect, it is too expensive and inefficient to be economically viable at the moment, and it remains to be seen whether this will change in the future.

The severe shortage in the supply of semiconductors recently had an adverse impact on the manufacture of electric vehicles in 2023, an industry which is already set to contend with a lithium supply crunch in the future.

In this context, quantum technology may offer a way out since it is not directly dependent on any external resource, rather it relies on the nature of matter itself to generate energy. Though the aforementioned developments are just small steps in the right direction, and it may take years before quantum technology becomes a viable source of energy creation, the potential here is immense. Quantum batteries could, for instance, offer a reliable replacement for lithium-ion batteries in the future. Given the environmental cost of lithium mining, not to mention its increasing scarcity, the world is in dire need of an alternative and quantum technology can do just that.

India continues to invest sizeable resources into alternative energy as part of its 2070 net zero goals, the National Green Hydrogen Mission constituting a recent example. What has not really been explored so far is quantum energy generation. With the National Quantum Mission having been announced in the 2023 budget, the groundwork has already been laid out. Including quantum energy generation under the ambit of the NQM would be a good way to kickstart Indias endeavour into this novel and exciting field, one which has the potential to completely transform the landscape of energy production as we know it. The future of energy generation may lie in the microscopic domain of quantum mechanics.

Prateek Tripathiis a Research Assistant Centre For Security Strategy and Technology at the Observer Research Foundation

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Why quantum technology may hold the key to alternative energy - Observer Research Foundation

Solving mysteries of the universe after measuring gravity in the quantum world – Tech Explorist

Gravity is best described as a curvature of space-time. Hence, it remains resistant to unifications with quantum theory. At microscopic scales, gravitational interaction is fundamentally weak and becomes prominent. It means that what happens to gravity in the microscopic regime where quantum effects dominate remains unknown, and whether quantum coherent effects of gravity become apparent remains unknown.

Thanks to new studies, scientists have successfully unraveled the mysterious forces of the universe. They figured out how to measure gravity on a microscopic level.

Using a new technique, they detected a weak gravitational pull on a tiny particle.

Their study could lead to new ways to find the elusive quantum gravity theory.

For this study, scientists used levitating magnets to detect gravity on microscopic particles small enough to border the quantum realm. The results could help experts find the missing puzzle piece in our picture of reality.

Lead author Tim Fuchs, from the University of Southampton, said,For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together.

Now that we have successfully measured gravitational signals at a negligible mass ever recorded, we are one step closer to finally realizing how it works in tandem.

From here, we will start scaling the source down using this technique until we reach the quantum world on both sides.

By understanding quantum gravity, we could solve some of the mysteries of our universe like how it began, what happens inside black holes, or uniting all forces into one big theory.

Scientists used a sophisticated setup involving superconducting devices, known as traps, with magnetic fields, sensitive detectors, and advanced vibration isolation.

It measured a weak pull, just 30aN, on a tiny particle 0.43mg in size by levitating it in freezing temperatures a hundredth of a degree above absolute zero about minus-273 degrees Celsius.

The results open the door for future experiments between even smaller objects and forces, said Professor of Physics Hendrik Ulbricht, also at the University of Southampton.

He added:We are pushing the boundaries of science that could lead to discoveries about gravity and the quantum world.

Our new technique that uses frigid temperatures and devices to isolate the vibration of the particle will likely prove the way forward for measuring quantum gravity.

Unravelling these mysteries will help us unlock more secrets about the universes fabric, from the tiniest particles to the grandest cosmic structures.

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Blocking out the noise: An interview with a quantum computing expert – McKinsey

February 29, 2024by Henning Soller

Quantum computing, which uses the principles of quantum mechanics to solve extremely complex problems, has recently seen significant advances that are making the technology much more practical. The possibility of surpassing todays computing limitations has become increasingly relevant given the exponentially growing need of resources for generative AI. Realizing solutions to otherwise unsolvable problems has generated interest from companies and significant funding for quantum computing companies.

While pursuing his PhD in physics, Thau Peronnin was part of the quantum-electronics group at cole normale suprieure, building the academic foundations for quantum computers. He cofounded Alice & Bob in 2020 to continue that work. The company has raised more than 30 million to date and is home to 80 physicists and engineers working to build the worlds first universal fault-tolerant quantum computer.

McKinsey partner Henning Soller sat down with Peronnin to learn his perspective on the value quantum computers can provide and how companies can prepare for their arrival.

Henning Soller: Whats the inherent advantage of a quantum computer? Where will its impact be most felt?

Thau Peronnin: Quantum will always be paired with classical computing to shape or prepare the data because quantum is only good at a handful of things. But these handful of things happen to have use cases everywhere.

Take AI, for example. On one hand, some believe Moores Law, which describes the scaling of compute power, has been slowing down and may plateau at some point. On the other hand, the scale of the infrastructure required to train generative AI models has basically reached global scale; it costs tens to hundreds of millions of dollars to train novel models. But were still falling very short of AI achieving human-level intelligence. Well need a profound disruption in computing to push it forward. This is what quantum could bring.

People are throwing around a lot of numbers in the hundreds of billions of dollars for the market potential for quantum. What all those numbers have in common is that they are unreasonably large. But they do indicate that there is a great potential for disruption through quantum. You must remember, though, that quantum is not the end goal. The end goal is to change the scale at which we can compute, which can drive better engineering and thereby increase value creation. This is what all the different types of computefrom telecommunications to AIhave been doing for the past 60 years. Quantum offers new breadth in that momentum of generating growth.

Where will that growth happen? Its a trade-off for companies and industries between how tech savvy and aware they are of what quantum offers and the potential quantum has for them. For example, since the 90s, financial institutions have understood the level of compute that can generate value for them, even though its not very transformative for humankind. In comparison, you have industries for which it could completely change the engineeringfrom pharmaceuticals to battery design in automotive. The problems that are most suited to quantum all boil down to material chemistry and biology.

Henning Soller: When do you think quantum computing will become a reality?

Thau Peronnin: I believe the signaling milestone for the beginning of quantum is happening now: a machine has been able to escape decoherence. That is, a logical qubit system is correcting its errors and is thereby demonstrating how quantum computing can become a reality. This means that we are now able to build machines that behave as promised. Next, we need to scale them up.

Error correction and managing decoherence will be key aspects from both a technology and a software perspective going forward. We can make major advancements with respect to the underlying technology, but we can also improve the algorithms and possibly even leverage decoherence.

The question is when the hardware will meet the requirements of real-world use cases and generate real-world value. For this, we need to increase the number of qubits, but right now, theres also a trend of innovating to reduce the required number of qubits. I believe these two trends will converge somewhere between 2027 and 2030.

Henning Soller: What can companies do at this stage to prepare for quantum computers?

Thau Peronnin: Quantum is all about first-mover advantage. If you take, for example, the automotive industry, the first company to be able to leverage novel hardware will be the first one to secure IP [intellectual property] on novel battery design. Once you start looking at quantum that way, you see that its going to cost maybe a few million dollars over several years to ramp up a decent team of four to six people internally so a company can expand as soon as its ready to move.

But its important not to get lost in proofs of concept. Companies should start by doing value calculations and prioritizing use cases. Then companies can carefully consider the trade-off and cost between being too early or too late in quantum.

Thau Peronnin is CEO and cofounder of Alice & Bob. Henning Soller is a partner in McKinseys Frankfurt office.

Comments and opinions expressed by interviewees are their own and do not represent or reflect the opinions, policies, or positions of McKinsey & Company or have its endorsement.

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Blocking out the noise: An interview with a quantum computing expert - McKinsey

New test could help detect effects of quantum gravity – Advanced Science News

Gaining an understanding of quantum gravity could help scientists uncover some of the Universe's deepest mysteries.

A new experimental technique to measure extremely weak gravitational forces with remarkable precision has recently emerged. The scientists behind the development believe it could one day help probe quantum effects in gravity a holy grail in modern theoretical physics.

By understanding quantum gravity, we could solve some of the mysteries of our Universe like how it began, what happens inside black holes, or uniting all forces into one big theory, Tim Fuchs, a physicist at Leiden University and one of the authors of the study, explained in a press release.

Although gravity is perhaps one of the most easily observed of all the fundamental forces, it has remained resistant to quantization, which is the incorporation of quantum theory that occurs on microscopic scales.

Quantum gravitational effects are too miniscule to be observed or be of relevance in most interactions of large bodies, such as stars and planets. However, they are expected to become visible when matter reaches intense densities and temperatures, orders of magnitude higher than anything we can achieve in a lab.

Since, the method proposed by the authors of the study emerges as a pivotal avenue for experimental exploration, potentially leading to a comprehensive theory of quantum gravity an imperative for unraveling the Universes deepest mysteries.

These extreme conditions make quantum gravity very difficult to study experimentally. The energies of particles in accelerators are too low for quantum-gravitational effects to manifest in their collisions, and astronomical observations have also not yet provided any information about these effects.

But in their recent study, Fuchs and his colleagues propose a sensitive experiment that will allow them to delve into how slight deviations in the behavior of gravitating bodies might deviate from predictions made by Einsteins theory of relativity, which describe gravity in classical terms. These deviations from classical behavior might encode previously unseen quantum effects in gravitational interactions.

For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together, said Fuchs. Now we have successfully measured gravitational signals at the smallest mass ever recorded, it means we are one step closer to finally realizing how it works in tandem.

In their study, the authors used a superconducting magnetic trap to study the subtle attraction between masses used to create a sort of artificial gravitational field and a test mass used as a probe.

The 0.43 milligram test mass is a neodymium-iron-boron magnet that levitated over a superconductor made of tantalum. This lack of physical support makes the test mass extremely sensitive to any external influence.

The gravitational field under study was generated by three 2.45 kg masses, evenly spaced on a wheel, which was placed on the side of the magnet. The wheels rotation changes their distance to the test mass, altering the magnitude of the gravitational attraction between them.

To suppress all mechanical and thermal noise, the experimental apparatus was suspended on a multi-stage spring system and chilled to temperatures near absolute zero (-273.15 degrees Celsius).

In their experiment, the team were able to measure a minute displacement of the test mass, which allowed them to determine tiny changes in the gravitational attraction between the source masses and the test mass. This was on the order of tens of attoNewtons 18 orders of magnitude lower compared to Earths gravitational pull on a 1 kg mass.

While initial measurements didnt reveal deviations from classical gravitational theory, the researchers anticipate that by reducing noise, as well as the source mass to the scale of the test mass, they will be able to probe the variations in the gravitational field so small that quantum effects in gravity will become noticeable. From here we will start scaling the source down using this technique until we reach the quantum world on both sides, Fuchs said.

We are pushing the boundaries of science that could lead to new discoveries about gravity and the quantum world, concluded Hendrik Ulbricht, a professor of physics at Hendrik Ulbricht and a coauthor of the study.

Our new technique that uses extremely cold temperatures and devices to isolate vibration of the particle will likely prove the way forward for measuring quantum gravity, he continued. Unraveling these mysteries will help us unlock more secrets about the Universes very fabric, from the tiniest particles to the grandest cosmic structures.

Reference: Tjerk H. Oosterkamp, et al, Measuring gravity with milligram levitated masses, Science Advances (2024). DOI: 10.1126/sciadv.adk2949

Feature image credit: merlinlightpainting on Pixabay

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New test could help detect effects of quantum gravity - Advanced Science News