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Imperial physicists have performed the double-slit experiment in time, using materials that can change optical properties in femtoseconds, providing insights into the nature of light and paving the way for advanced materials that can control light in both space and time.

Imperial physicists have recreated the famous double-slit experiment, which showed light behaving as particles and a wave, in time rather than space.

In a groundbreaking development, Imperial College London physicists have recreated the historic double-slit experiment, which demonstrated light behaving as both particles and a wave, in time rather than space. By using materials that can alter their optical properties in femtoseconds, the team successfully fired light through a thin film of indium-tin-oxide, creating temporal slits for light to pass through. The experiment not only offers insights into the fundamental nature of light but also serves as a stepping stone for developing advanced materials to control light in both space and time. These materials could potentially contribute to new technologies and help study fundamental physics phenomena, such as black holes.

The experiment relies on materials that can change their optical properties in fractions of a second, which could be used in new technologies or to explore fundamental questions in physics.

The original double-slit experiment, performed in 1801 by Thomas Young at the Royal Institution, showed that light acts as a wave. Further experiments, however, showed that light actually behaves as both a wave and as particles revealing its quantum nature.

These experiments had a profound impact on quantum physics, revealing the dual particle and wave nature of not just light, but other particles including electrons, neutrons, and whole atoms.

Now, a team led by Imperial College London physicists has performed the experiment using slits in time rather than space. They achieved this by firing light through a material that changes its properties in femtoseconds (quadrillionths of a second), only allowing light to pass through at specific times in quick succession.

Lead researcherProfessor Riccardo Sapienza, from the Department of Physics at Imperial, said: Our experiment reveals more about the fundamental nature of light while serving as a stepping-stone to creating the ultimate materials that can minutely control light in both space and time.

Details of the experiment are published today (April 3, 2023) in the journal Nature Physics.

Project member Romain Tirole adjusts the equipment used in the study at Imperial College London. Credit: Thomas Angus, Imperial College London

The original double-slit setup involved directing light at an opaque screen with two thin parallel slits in it. Behind the screen was a detector for the light that passed through.

To travel through the slits as a wave, light splits into two waves that go through each slit. When these waves cross over again on the other side, they interfere with each other. Where peaks of the wave meet, they enhance each other, but where a peak and a trough meet, they cancel each other out. This creates a striped pattern on the detector of regions of more light and less light.

Light can also be parcelled up into particles called photons, which can be recorded hitting the detector one at a time, gradually building up the striped interference pattern. Even when researchers fired just one photon at a time, the interference pattern still emerged, as if the photon split in two and travelled through both slits.

In the classic version of the experiment, light emerging from the physical slits changes its direction, so the interference pattern is written in the angular profile of the light. Instead, the time slits in the new experiment change the frequency of the light, which alters its colour. This created colours of light that interfere with each other, enhancing and cancelling out certain colours to produce an interference-type pattern.

The material the team used was a thin film of indium-tin-oxide, which forms most mobile phone screens. The material had its reflectance changed by lasers on ultrafast timescales, creating the slits for light. The material responded much quicker than the team expected to the laser control, varying its reflectivity in a few femtoseconds.

The material is a metamaterial one that is engineered to have properties not found in nature. Such fine control of light is one of the promises of metamaterials, and when coupled with spatial control, could create new technologies and even analogues for studying fundamental physics phenomena like black holes.

Co-authorProfessor Sir John Pendrysaid: The double time slits experiment opens the door to a whole new spectroscopy capable of resolving the temporal structure of a light pulse on the scale of one period of the radiation.

The team next want to explore the phenomenon in a time crystal, which is analogous to an atomic crystal, but where the optical properties vary in time.

Co-authorProfessor Stefan Maiersaid: The concept of time crystals has the potential to lead to ultrafast, parallelized optical switches.

Reference: Double-slit time diffraction at optical frequencies by Romain Tirole, Stefano Vezzoli, Emanuele Galiffi, Iain Robertson, Dries Maurice, Benjamin Tilmann, Stefan A. Maier, John B. Pendry and Riccardo Sapienza, 3 April 2023, Nature Physics.DOI: 10.1038/s41567-023-01993-w

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Time-Bending Experiment: Physicists Reveal Quantum Nature of ... - SciTechDaily

It is hard to shake the intuition that theres a real and objective physical world out there. If I see an umbrella on top of a shelf, I assume you do too. And if I dont look at the umbrella, I expect it to remain there as long as nobody steals it. But the theory of quantum mechanics, which governs the micro-world of atoms and particles, threatens this commonsense view.

The fourth episode of our podcast Great Mysteries of Physics hosted by me, Miriam Frankel, science editor at The Conversation, and supported by FQxI, the Foundational Questions Institute is all about the strange world of quantum mechanics.

According to quantum theory, each system, such as a particle, can be described by a wave function, which evolves over time. The wave function allows particles to hold multiple contradictory features, such as being in several different places at once this is called a superposition. But oddly, this is only the case when nobodys looking.

Although each potential location in a superposition has a certain probability of appearing, the second you observe it, the particle randomly picks one breaking the superposition. Physicists often refer to this as the wave function collapsing. But why should nature behave differently depending on whether we are looking or not? And why should it be random?

Not everyone is worried. If you want to explain everything we can observe in our experiments without randomness, you have to go through some really weird and long-winded explanations that I am much more uncomfortable with, argues Marcus Huber, a professor of quantum information at the Technical University of Vienna. And indeed, you can get rid of randomness if you accept that the future can influence the past, that theres more than one outcome to every measurement or that everything in the universe is predetermined since the dawn of time.

Another problem is that quantum mechanics seems to give rise to contradictory facts. Imagine a scientist, Lisa, inside a lab measuring the location of a particle. Before her colleague, Nikhil, knocks on the lab door and asks what outcome she saw, he would measure Lisa as being in a superposition of both branches one where she sees the particle here and one where she sees the particle there. But at the same time, Lisa herself may be convinced that that she has a definite answer as to where the particle is.

That means that these two people will say that the state of reality is different theyd have different facts about where the particle is.

There are may other oddities about quantum mechanics, too. Particles can be entangled in a way that enables them to somehow share information instantaneously even if theyre light years apart, for example. This challenges another common intution: that objects need a physical mediator to interact.

Physicists have therefore long debated how to interpret quantum mechanics. Is it a true and objective description of reality? If so, what happens to all the possible outcomes that we dont measure? The many worlds interpretation argues they do happen but in parallel universes.

Another set of interpretations, collectively known as the Copenhagen interpretation, suggests quantum mechanics is to some extent a users manual rather than a perfect description of reality. The Copenhagen interpretations what they share is at least a partial step back from the full-blown descriptive aim of physics, explains Chris Timpson, a philosopher of physics at the University of Oxford. So the quantum state, this thing which describes these lovely superpositions, thats just a tool for making predictions about the behaviour of macroscopic measurement scenarios.

But why dont we see quantum effect on the scale of humans? Chiara Marletto, a quantum physicist at the University of Oxford, has developed a meta-theory called constructor theory which aims to encompass all of physics based solely on simple principles about which physical transformations in the universe are ultimately possible, which are impossible, and why.

She hopes it can help us understand why we dont see quantum effects on the macroscopic scale of humans. Theres nothing [in the laws of physics] that says its impossible to have quantum effects at the scale of a human being, she says. So either we discover a new principle that says that they really are impossible which would be interesting or in the absence of that, it is more a question of trying harder to create conditions in the laboratory to bring these effects about.

Another problem with quantum mechanics is that it isnt compatible with general relativity, which describes nature on the largest of scales. Marletto is using constructor theory to try to find ways to combine the two. She has also come up with some experiments which could test such models and rule out certain interpretations of quantum mechanics.

You can listen to Great Mysteries of Physics via any of the apps listed above, our RSS feed, or find out how else to listen here. You can also read a transcript of the episode here.

If so, youll be interested in our free daily newsletter. Its filled with the insights of academic experts, written so that everyone can understand whats going on in the world. With the latest scientific discoveries, thoughtful analysis on political issues and research-based life tips, each email is filled with articles that will inform you and often intrigue you.

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Great Mysteries of Physics 4: does objective reality exist? - The Conversation

What is quantum theory of consciousness?

The quantum theory of consciousness is a theoretical approach that seeks to explain the relationship between consciousness and the principles of quantum mechanics. It suggests that consciousness is a fundamental aspect of the universe, and that the principles of quantum mechanics play a crucial role in its functioning.

At its core, the quantum theory of consciousness suggests that consciousness arises from the quantum mechanical interactions between particles in the brain. According to this theory, the brain is not simply a classical, deterministic system, but rather a quantum system that is governed by the principles of quantum mechanics. These principles, which include concepts such as entanglement, superposition, and wave-particle duality, allow for a much more complex and dynamic system than classical mechanics.

One of the key ideas behind the quantum theory of consciousness is the concept of nonlocality. Nonlocality refers to the idea that particles can become instantaneously connected. Even if separated by vast distances. This concept became observed in numerous experiments. And considered to be a fundamental principle of quantum mechanics. The theory suggests that consciousness arises from these nonlocal interactions between particles in the brain, and that this allows for a kind of information processing that is not possible in classical systems.

While the quantum theory of consciousness remains a controversial and speculative area of research, it has gained increasing attention from both scientists and philosophers. Proponents of the theory argue that it provides a more comprehensive and holistic understanding of consciousness, and that it has the potential to shed light on a range of phenomena, from near-death experiences to telepathy. However, critics argue that the theory is not supported by empirical evidence, and that it relies on vague and poorly defined concepts.

In conclusion, the quantum theory of consciousness is a theoretical approach that seeks to explain the relationship between consciousness and the principles of quantum mechanics. It suggests that consciousness arises from the interactions between particles in the brain, and that the principles of quantum mechanics play a crucial role in its functioning. While the theory remains controversial, it has the potential to provide a more comprehensive understanding of consciousness and its place in the universe.

Is particle physics the same as quantum?

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What is quantum theory of consciousness? - Rebellion Research

Imperial physicists conducted the double-splitting experiment over time, using materials that could change optical properties in femtoseconds, providing insights into the nature of light and paving the way for advanced materials that could control light in both space and time.

Imperial physicists recreated the famous double-splitting experiment, which showed that light behaves as a particle and wave in time rather than space.

In an amazing development,[{ attribute=>Imperial College London physicists have recreated the historic double-slit experiment, which demonstrated light behaving as both particles and a wave, in time rather than space. By using materials that can alter their optical properties in femtoseconds, the team successfully fired light through a thin film of indium-tin-oxide, creating temporal slits for light to pass through. The experiment not only offers insights into the fundamental nature of light but also serves as a stepping stone for developing advanced materials to control light in both space and time. These materials could potentially contribute to new technologies and help study fundamental physics phenomena, such as black holes.

The experiment relies on materials that can change their optical properties in fractions of a second, which could be used in new technologies or to explore fundamental questions in physics.

The original double-slit experiment, performed in 1801 by Thomas Young at the Royal Institution, showed that light acts as a wave. Further experiments, however, showed that light actually behaves as both a wave and as particles revealing its quantum nature.

These experiments had a profound impact on quantum physics, revealing the dual particle and wave nature of not just light, but other particles including electrons, neutrons, and whole atoms.

Now, a team led by Imperial College London physicists has performed the experiment using slits in time rather than space. They achieved this by firing light through a material that changes its properties in femtoseconds (quadrillionths of a second), only allowing light to pass through at specific times in quick succession.

Lead researcherProfessor Riccardo Sapienza, from the Department of Physics at Imperial, said: Our experiment reveals more about the fundamental nature of light while serving as a stepping-stone to creating the ultimate materials that can minutely control light in both space and time.

Details of the experiment are published today (April 3, 2023) in the journal Nature Physics.

Project member Romain Tirole adjusts the equipment used in the study at Imperial College London. Credit: Thomas Angus, Imperial College London

The original double-slit setup involved directing light at an opaque screen with two thin parallel slits in it. Behind the screen was a detector for the light that passed through.

To travel through the slits as a wave, light splits into two waves that go through each slit. When these waves cross over again on the other side, they interfere with each other. Where peaks of the wave meet, they enhance each other, but where a peak and a trough meet, they cancel each other out. This creates a striped pattern on the detector of regions of more light and less light.

Light can also be parcelled up into particles called photons, which can be recorded hitting the detector one at a time, gradually building up the striped interference pattern. Even when researchers fired just one photon at a time, the interference pattern still emerged, as if the photon split in two and travelled through both slits.

In the classic version of the experiment, light emerging from the physical slits changes its direction, so the interference pattern is written in the angular profile of the light. Instead, the time slits in the new experiment change the frequency of the light, which alters its colour. This created colours of light that interfere with each other, enhancing and cancelling out certain colours to produce an interference-type pattern.

The material the team used was a thin film of indium-tin-oxide, which forms most mobile phone screens. The material had its reflectance changed by lasers on ultrafast timescales, creating the slits for light. The material responded much quicker than the team expected to the laser control, varying its reflectivity in a few femtoseconds.

The material is a metamaterial one that is engineered to have properties not found in nature. Such fine control of light is one of the promises of metamaterials, and when coupled with spatial control, could create new technologies and even analogues for studying fundamental physics phenomena like black holes.

Co-authorProfessor Sir John Pendrysaid: The double time slits experiment opens the door to a whole new spectroscopy capable of resolving the temporal structure of a light pulse on the scale of one period of the radiation.

The team next want to explore the phenomenon in a time crystal, which is analogous to an atomic crystal, but where the optical properties vary in time.

Co-authorProfessor Stefan Maiersaid: The concept of time crystals has the potential to lead to ultrafast, parallelized optical switches.

Reference: Double-slit time diffraction at optical frequencies by Romain Tirole, Stefano Vezzoli, Emanuele Galiffi, Iain Robertson, Dries Maurice, Benjamin Tilmann, Stefan A. Maier, John B. Pendry and Riccardo Sapienza, 3 April 2023, Nature Physics.DOI: 10.1038/s41567-023-01993-w

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Physicists reveal the quantum nature of light in a new dimension - The Pilot

OAKLAND, Calif March 31 (Reuters) - Singapore-based software startup Horizon Quantum Computing on Friday said it raised $18.1 million to expand its engineering team and speed up product development.

The company, founded in 2018, created a programming language called Helium for quantum computers, designed to make it easier to tackle complex problems.

Today to use quantum computers developers either have to program in terms of elementary operations, or instead rely on pre-written programs from other software makers, said Horizon Chief Executive Joe Fitzsimons.

Quantum computers, based on quantum physics, could potentially perform some calculations millions of times faster than the current fastest super computers. But they are mostly still in research mode and have yet to create an advantage over classic computers for anything significant.

While there are over an estimated 100 million software developers, Fitzsimons said there are only a few hundred who would be able to program quantum computers from scratch, and that banks and pharmaceutical companies will want to develop their own code rather than rely on pre-written ones.

"In some sense their algorithms are part of their competitive edge. So how do you enable them to do that development while recognizing that the talent pool is very, very, very small for this area?" said Fitzsimons.

To help alleviate the talent shortage, the company plans to create a translation layer that will make it possible for software developers using classical computer programming languages such as C++ or Python to use those languages for quantum computers directly.

Horizon Quantum Computing said it is also planning to open its first European offices in Ireland, where it is building its new engineering center.

The company said Sequoia Capital India, China's Tencent Holdings Ltd (0700.HK), and Singapore government's tech investment firm SGInnovate were among the investors funding this round. The company has so far raised a total of about $21 million.

Reporting By Jane Lanhee LeeEditing by Bill Berkrot

Our Standards: The Thomson Reuters Trust Principles.

Thomson Reuters

Reports on global trends in computing from covering semiconductors and tools to manufacture them to quantum computing. Has 27 years of experience reporting from South Korea, China, and the U.S. and previously worked at the Asian Wall Street Journal, Dow Jones Newswires and Reuters TV. In her free time, she studies math and physics with the goal of grasping quantum physics.

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Singapore-based software startup Horizon Quantum Computing ... - Reuters