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Archive for the ‘quantum physics’ category: Page 174

Mar 16, 2023

Magnetism fosters unusual electronic order in quantum material

Posted by in categories: energy, quantum physics

Physicists were surprised by the 2022 discovery that electrons in magnetic iron-germanium crystals could spontaneously and collectively organize their charges into a pattern featuring a standing wave. Magnetism also arises from the collective self-organization of electron spins into ordered patterns, and those patterns rarely coexist with the patterns that produce the standing wave of electrons physicists call a charge density wave.

In a study published this week in Nature Physics, Rice University physicists Ming Yi and Pengcheng Dai, and many of their collaborators from the 2022 study, present an array of experimental evidence that shows their charge density wave discovery was rarer still, a case where the magnetic and electronic orders don’t simply coexist but are directly linked.

“We found magnetism subtly modifies the landscape of electron energy states in the material in a way that both promotes and prepares for the formation of the charge density wave,” said Yi, a co-corresponding author of the study.

Mar 16, 2023

A quantum playground for exploring light topology

Posted by in categories: computing, quantum physics

A quantum device fabricated by Zhejiang University researchers could help to advance the design of quantum computers as it offers topological control over the units that store information within them. The team’s results were published in Science in December 2022.

Since their discovery around 2007, , known as , have been generating a lot of excitement due to their intriguing properties. For example, they are insulating in their interior, but conducting on their surfaces. This property stems from the topological nature of these materials, which makes them robust to deformations, so electrons moving along their surfaces resist any obstacles that might obstruct their flow.

Continue reading “A quantum playground for exploring light topology” »

Mar 16, 2023

‘Counterportation’: Quantum breakthrough paves way for world-first experimental wormhole

Posted by in categories: computing, cosmology, particle physics, quantum physics

One of the first practical applications of the much-hyped but little-used quantum computing technology is now within reach, thanks to a unique approach that sidesteps the major problem of scaling up such prototypes.

The invention, by a University of Bristol physicist, who gave it the name “counterportation,” provides the first-ever practical blueprint for creating in the lab a wormhole that verifiably bridges space, as a probe into the inner workings of the universe.

By deploying a novel computing scheme, revealed in the journal Quantum Science and Technology, which harnesses the basic laws of physics, a small object can be reconstituted across space without any particles crossing. Among other things, it provides a “smoking gun” for the existence of a physical reality underpinning our most accurate description of the world.

Mar 16, 2023

“Counterportation” — Landmark Quantum Breakthrough Paves Way for World-First Experimental Wormhole

Posted by in categories: computing, cosmology, quantum physics

Quantum computing technology is within reach due to an innovative method that overcomes the significant challenge of scaling up these prototypes.

The invention, by a University of Bristol physicist, who gave it the name ‘counterportation’, provides the first-ever practical blueprint for creating in the lab a wormhole that verifiably bridges space, as a probe into the inner workings of the universe.

Mar 15, 2023

The physicist betting that space-time isn’t quantum after all

Posted by in category: quantum physics

Most experts think we have to tweak general relativity to fit with quantum theory. Physicist Jonathan Oppenheim isn’t so sure, which is why he’s made a 5000:1 bet that gravity isn’t a quantum force.

By Joshua Howgego

Mar 15, 2023

Quantum Imaging Doubles Microscope Resolution

Posted by in category: quantum physics

Using entangled photons instead of classical light gives microscopes super-resolution.

Mar 15, 2023

Quantum Computing Is the Future, and Schools Need to Catch Up

Posted by in categories: computing, education, quantum physics

Top universities are finally bringing the excitement of the quantum future into the classroom.

Mar 15, 2023

High-performance photon detectors to combat spies in the quantum computing age

Posted by in categories: computing, particle physics, quantum physics

How can we combat data theft, which is a real issue for society? Quantum physics has the solution. Its theories make it possible to encode information (a qubit) in single particles of light (a photon) and to circulate them in an optical fiber in a highly secure way. However, the widespread use of this telecommunications technology is hampered in particular by the performance of the single-photon detectors.

A team from the University of Geneva (UNIGE), together with the company ID Quantique, has succeeded in increasing their speed by a factor of twenty. This innovation, published in the journal Nature Photonics, makes it possible to achieve unprecedented performances in quantum .

Buying a train ticket, booking a taxi, getting a meal delivered: these are all transactions carried out daily via . These are based on payment systems involving an exchange of secret information between the user and the bank. To do this, the bank generates a , which is transmitted to their customer, and a private key, which it keeps secret. With the public key, the user can modify the information, make it unreadable and send it to the bank. With the private key, the bank can decipher it.

Mar 15, 2023

To Save Physics, Experts Suggest We Need to Assume The Future Can Affect The Past

Posted by in categories: particle physics, quantum physics, space

In 2022, the physics Nobel prize was awarded for experimental work showing that the quantum world must break some of our fundamental intuitions about how the Universe works.

Many look at those experiments and conclude that they challenge “locality” – the intuition that distant objects need a physical mediator to interact. And indeed, a mysterious connection between distant particles would be one way to explain these experimental results.

Others instead think the experiments challenge “realism” – the intuition that there’s an objective state of affairs underlying our experience. After all, the experiments are only difficult to explain if our measurements are thought to correspond to something real.

Mar 15, 2023

Quantum causality emerging in a delayed-choice quantum Cheshire Cat experiment with neutrons

Posted by in categories: information science, quantum physics

The Eqs. (3a) and (3b) suggest two important features of the location of neutrons and the spin by switching the choice of the post-selection: (i) The first lines indicate that the neutrons are found to be localized in different paths by switching the choice of the post-selection; they are found in the path I and II by applying the post-selection \({|{\Psi ^{+}_f}\rangle }\) and \({|{\Psi ^{-}_f}\rangle }\), respectively. (ii) The lines of the second part of the equations indicate that the spin in the different paths is found to be affected by switching the choice of the post-selection; the spin in path II and I is affected by applying the post-selection \({|{\Psi ^{+}_f}\rangle }\) and \({|{\Psi ^{-}_f}\rangle }\), respectively. Note that, in both choices of the post-selection, neutron and spin are localized in different paths, i.e., the location of the cat itself and its grin are interchanged by switching the choices of the post-selection. Since measurement of the locations of the neutron and the spin in the interferometer can be carried out independently of the delayed-choice process, the picking of a direction for post-selection, the influence of the delayed-choice on the preceding measurements can be investigated. We would like to point out that the experimental proposal in a recent publication35, contains a delayed choice scenario, too. The difference to the experiment presented in this report is that the authors of35 suggest a setup where two properties of the same system, represented by two non-commuting observables, are separated. In contrast to that, we deal in our experiment with the separation of one property from the system itself, hereby constituting the phenomenon of disembodiment. Further we would like to point out that in their Gedanken-experiment the effect of a change in the pre-selection is discussed that in our view has no retro-causal implications.

The experiment was carried out at the S18 silicon-perfect-crystal interferometer beam line at the high flux reactor at the Institute Laue Langevin. A schematic view of the experimental set-up is shown in Fig. 2.