Slide: 1 / of 1. Caption: Getty Images

At the Ludwig-Maximilian University of Munich, the basement of the physics building is connected to the economics building by nearly half a miles worth of optical fiber. It takes a photon three millionths of a secondand a physicist, about five minutesto travel from one building to the other. Starting in November 2015, researchers beamed individual photons between the buildings, over and over again for seven months, for a physics experiment that could one day help secure your data.

Their immediate goal was to settle a decades-old debate in quantum mechanics: whether the phenomenon known as entanglement actually exists. Entanglement, a cornerstone of quantum theory, describes a bizarre scenario in which the fate of two quantum particlessuch as a pair of atoms, or photons, or ionsare intertwined. You could separate these two entangled particles to opposite sides of the galaxy, but when you mess with one, you instantaneously change the other. Einstein famously doubted that entanglement was actually a thing and dismissed it as spooky action at a distance.

Over the years, researchers have run all sorts of complicated experiments to poke at the theory. Entangled particles exist in nature, but theyre extremely delicate and hard to manipulate. So researchers make them, often using lasers and special crystals, in precisely controlled settings to test that the particles behave the way prescribed by theory.

In Munich, researchers set about their test in two laboratories, one in the physics building, the other in economics. In each lab, they used lasers to coax a single photon out of a rubidium atom; according to quantum mechanics theory, colliding those two photons would entangle the rubidium atoms. That meant they had to get the atoms in both departments to emit a photon pretty much simultaneouslyaccomplished by firing a tripwire electric signal from one lab to the other. Theyre synchronized to less than a nanosecond, says physicist Harald Weinfurter of the Ludwig-Maximilian University of Munich.

The researchers collided the two photons by sending one of them over the optical fiber. Then they did it again. And again, tens of thousands of times, followed up by statistical analysis. Even though the atoms were separated by a quarter of a milealong with all the impinging buildings, roads, and treesthe researchers found the two particles properties were correlated. Entanglement exists.

So, quantum mechanics isnt broken which is exactly what the researchers expected. In fact, this experiment basically shows the same results as a series of similar tests that physicists started to run in 2015. Theyre known as Bell tests, named for John Stewart Bell, the northern Irish physicist whose theoretical work inspired them. Few physicists still doubt that entanglement exists. I dont think theres any serious or large-scale concern that quantum mechanics is going to be proven wrong tomorrow, says physicist David Kaiser of MIT, who wasnt involved in the research. Quantum theory has never, ever, ever let us down.

But despite their predictable results, researchers find Bell tests interesting for a totally different reason: They could be essential to the operation of future quantum technologies. In the course of testing this strange, deep feature of nature, people realized these Bell tests could be put to work, says Kaiser.

For example, Googles baby quantum computer, which it plans to test later this year, uses entangled particles to perform computing tasks. Quantum computers could execute certain algorithms much faster because entangled particles can hold and manipulate exponentially more information than regular computer bits. But because entangled particles are so difficult to control, engineers can use Bell tests to verify their particles are actually entangled. Its an elementary test that can show that your quantum logic gate works, Weinfurter says.

Bell tests could also be useful in securing data, says University of Toronto physicist Aephraim Steinberg, who was not involved in the research. Currently, researchers are developing cryptographic protocols based on entangled particles. To send a secure message to somebody, youd encrypt your message using a cryptographic key encoded in entangled quantum particles. Then you send your intended recipient the key. Every now and then, you stop and do a Bell test, says Steinberg. If a hacker tries to intercept the key, or if the key was defective in the first place, you will be able to see it in the Bell tests statistics, and you would know that your encrypted message is no longer secure.

In the near future, Weinfurters group wants to use their experiment to develop a setup that could send entangled particles over long distances for cryptographic purposes. But at the same time, theyll keep performing Bell tests to provebeyond any inkling of a doubtthat entanglement really exists. Because whats the point of developing applications on top of an illusion?

Read this article:
The Bizarre Quantum Test That Could Keep Your Data Secure - WIRED

The concept of building a quantum computer with topological qubits had been knocking around Microsoft for nearly 15 years.

At the companys Redmond campus, later expanding into its Station Q centre at the University of California, researchers investigated this complex, yet beautiful mathematical theory as Microsofts quantum guru Michael Freedman once described it.

It remained just that a beautiful theory for years. Then something changed.

Suddenly in late 2016, Microsoft announced Station Q would expand to eight labs worldwide including one at the Quantum Nanoscience Laboratory at the University of Sydney. Four heavyweight academic hires were made. An 'inflection point' had been reached, a release stated.

Why are they now switching on? How much should I read into that? says Professor David Reilly, director of Station Qs new Sydney lab. I think you can read plenty into that.

Is Anyon out there?

The topological approach to forming qubits uses quasiparticles called non-abellian anyons.

We've realised that the only way to really scale is to build much better qubits. Qubits that are inherently, intrinsically immune to noise and immune to disturbances from the environment, says Reilly.

In most approaches to building quantum systems, information is encoded in the properties of particles. That makes the systems very fragile as any disturbances from the environment can destroy a particles quantum state.

According to Microsoft, topological qubits are better able to withstand heat and electrical noise, which allows them to remain in a stable quantum state for longer. By encoding the information not on the quasiparticle but in the order the positions of the anyons are swapped around (called braiding), topological qubits offer a more viable way to make a scalable, usable quantum computer.

The quasiparticles themselves remain something of a riddle. Non-abellian anyons cant be seen with any kind of microscope but they can be measured with high-precision devices. Probably. Certainly there is no consensus among physicists as to whether they are real or not.

As Microsofts Alex Bocharov confidently put it to Nature, the company is pretty sure that they exist.

We reached a point where the experiments were convincing enough that now we should actually try and construct technology from it. And that's where we are today, Reilly adds.

Faith at scale

Backing topological qubits is as much about belief in the approach, Reilly says, as doubt in all the others.

It's a double-edged sword. For me personally some of the decision to go in this direction is born out of a pessimistic view. It's faith in this approach and the reality is it's pessimism that the other existing approaches can really go the distance, he says.

Google and IBM back the superconducting loop approach to building qubits, while Intel and the Commonwealth Bank and Telstra backed Centre for Quantum Computation and Communication Technology at UNSW in Sydney, are pursuing a silicon-based method.

The difference between demonstrating the basic operation of one single device in a university lab and publishing a very nice paper, and what it's going to take to bring that technology to scale I think these are vastly different activities, Reilly says. It becomes pretty depressing and I don't see it.

The ability to scale is key to Microsofts quantum efforts. Its ambition goes way beyond the lab.

It's all about having the fundamental building blocks that can take you to millions of qubits, Reilly says. It's all about going the distance.

Error: Please check your email address.

Tags Sydneytopological qubitKinectquantumquantum computingTelstraHoloLensnanotechnologyStation QMicrosoftRedmondunswXboxCommonwealth Bank of Australia

More about Commonwealth BankGoogleIBMIntelMicrosoftQQuantumReillyTechnologyUniversity of SydneyUNSWXbox

See the rest here:
Inside Microsoft's 'soup to nuts' quantum computing ramp-up - Computerworld Australia

In Brief Scientists have discovered a fundamentally new state of matter: 3D quantum liquid crystals. These have the potential to advance microchip technology and quantum computing. 3D Quantum Liquid Crystals

Caltech physicists at the Institute for Quantum Information and Matter have discovered the first 3D quantum liquid crystal. This is a new state of matter they expect will have applications in ultrafast quantum computing, and the researchers believe this discovery is just the tip of the iceberg.

The molecules of standard liquid crystals flow freely as if they were a liquid, but stay directionally oriented like a solid. Liquid crystals can be made artificially, like those in display screens of electronic devices, or found in nature, like those found in biological cell membranes. Quantum liquid crystals were first discovered in 1999; their molecules behave much like those in regular liquid crystals, but their electrons prefer to orient themselves along certain axes.

The electrons of the 3D quantum liquid crystals exhibit different magnetic properties depending on the direction they flow along a given axis. Practically speaking, this means that electrifying these materials changes them into magnets, or changes the strength or orientation of their magnetism.

The research team expects that 3D quantum liquid crystals might advance the field of designing and creating more efficient computer chips by helping computer scientists exploit the direction that electrons spin. The 3D quantum liquid crystal discovery could also advance us along the road toward building quantum computers, which will decrypt codes and make other calculations at much higher speeds thanks to the quantum nature of particles.

Achieving a quantum computer is a challenge, because quantum effects are delicate and transient. They can be changed or destroyed simply through theirinteractions with the surrounding environments. This problem may be solved by a technique requiringa special material called a topological superconductor which is where the 3D quantum liquid crystals come in.

In the same way that 2D quantum liquid crystals have been proposed to be a precursor to high-temperature superconductors, 3D quantum liquid crystals could be the precursors to the topological superconductors weve been looking for, Caltech assistant professor of physics David Hsieh, principal investigator on the new study, said in an interview for a Caltech press release.

Rather than rely on serendipity to find topological superconductors, we may now have a route to rationally creating them using 3D quantum liquid crystals, Hsieh lab postdoctoral scholar John Harter, the lead author of the new study published in Science, said in the press release. That is next on our agenda.

Continue reading here:
Scientists: We Have Detected the Existence of a Fundamentally New State of Matter - Futurism

Wikimedia Commons

In a world where we are relying increasingly on computing, to share our information and store our most precious data, the idea of living without computers might baffle most people.

But if we continue to follow the trend that has been in place since computers were introduced, by 2040 we will not have the capability to power all of the machines around the globe, according to a recent report by the Semiconductor Industry Association.

To prevent this, the industry is focused on finding ways to make computing more energy efficient, but classical computers are limited by the minimum amount of energy it takes them to perform one operation.

This energy limit is named after IBM Research Lab's Rolf Landauer, who in 1961 found that in any computer, each single bit operation must use an absolute minimum amount of energy. Landauer's formula calculated the lowest limit of energy required for a computer operation, and in March this year researchers demonstrated it could be possible to make a chip that operates with this lowest energy.

It was called a "breakthrough for energy-efficient computing" and could cut the amount of energy used in computers by a factor of one million. However, it will take a long time before we see the technology used in our laptops; and even when it is, the energy will still be above the Landauer limit.

This is why, in the long term, people are turning to radically different ways of computing, such as quantum computing, to find ways to cut energy use.

Quantum computing takes advantage of the strange ability of subatomic particles to exist in more than one state at any time. Due to the way the tiniest of particles behave, operations can be done much more quickly and use less energy than classical computers.

In classical computing, a bit is a single piece of information that can exist in two states 1 or 0. Quantum computing uses quantum bits, or 'qubits' instead. These are quantum systems with two states. However, unlike a usual bit, they can store much more information than just 1 or 0, because they can exist in any superposition of these values.

"Traditionally qubits are treated as separated physical objects with two possible distinguishable states, 0 and 1," Alexey Fedorov, physicist at the Moscow Institute of Physics and Technology told WIRED.

"The difference between classical bits and qubits is that we can also prepare qubits in a quantum superposition of 0 and 1 and create nontrivial correlated states of a number of qubits, so-called 'entangled states'."

D-Wave

A qubit can be thought of like an imaginary sphere. Whereas a classical bit can be in two states - at either of the two poles of the sphere - a qubit can be any point on the sphere. This means a computer using these bits can store a huge amount more information using less energy than a classical computer.

Last year, a team of Google and Nasa scientists found a D-wave quantum computer was 100 million times faster than a conventional computer. But moving quantum computing to an industrial scale is difficult.

IBM recently announced its Q division is developing quantum computers that can be sold commercially within the coming years. Commercial quantum computer systems "with ~50 qubits" will be created "in the next few years," IBM claims. While researchers at Google, in Nature comment piece, say companies could start to make returns on elements of quantum computer technology within the next five years.

Computations occur when qubits interact with each other, therefore for a computer to function it needs to have many qubits. The main reason why quantum computers are so hard to manufacture is that scientists still have not found a simple way to control complex systems of qubits.

Now, scientists from Moscow Institute of Physics and Technology and Russian Quantum Centre are looking into an alternative way of quantum computing. Not content with single qubits, the researchers decided to tackle the problem of quantum computing another way.

"In our approach, we observed that physical nature allows us to employ quantum objects with several distinguishable states for quantum computation," Fedorov, one of the authors of the study, told WIRED.

The team created qubits with various different energy "levels", that they have named qudits. The "d" stands for the number of different energy levels the qudit can take. The term "level" comes from the fact that typically each logic state of a qubit corresponds to the state with a certain value of energy - and these values of possible energies are called levels.

"In some sense, we can say that one qudit, quantum object with d possible states, may consist of several 'virtual' qubits, and operating qudit corresponds to manipulation with the 'virtual' qubits including their interaction," continued Federov.

"From the viewpoint of abstract quantum information theory everything remains the same but in concrete physical implementation many-level system represent potentially useful resource."

Quantum computers are already in use, in the sense that logic gates have been made using two qubits, but getting quantum computers to work on an industrial scale is the problem.

"The progress in that field is rather rapid but no one can promise when we come to wide use of quantum computation," Fedorov told WIRED.

Elsewhere, in a step towards quantum computing, researchers have guided electrons through semiconductors using incredibly short pulses of light. Inside the weird world of quantum computers

These extremely short, configurable pulses of light could lead to computers that operate 100,000 times faster than they do today. Researchers, including engineers at the University of Michigan, can now control peaks within laser pulses of just a few femtoseconds (one quadrillionth of a second) long. The result is a step towards "lightwave electronics" which could eventually lead to a breakthrough in quantum computing.

A bizarre discovery recently revealed that cold helium atoms in lab conditions on Earth abide by the same law of entropy that governs the behaviour of black holes. What are black holes? WIRED explains

The law, first developed by Professor Stephen Hawking and Jacob Bekenstein in the 1970s, describes how the entropy, or the amount of disorder, increases in a black hole when matter falls into it. It now seems this behaviour appears at both the huge scales of outer space and at the tiny scale of atoms, specifically those that make up superfluid helium.

"It's called an entanglement area law, explained Adrian Del Maestro, physicist at the University of Vermont. "It points to a deeper understanding of reality and could be a significant step toward a long-sought quantum theory of gravity and new advances in quantum computing.

See the rest here:
quantum computing - WIRED UK