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Smooth sailing for electrons in graphene: Physicists directly measured, at nanometer resolution, the fluid-like flow of electrons in graphene

ScienceDaily - General News Websites

Physicists have directly measured, for the first time at nanometer resolution, the fluid-like flow of electrons in graphene. The results have applications in developing new, low-resistance materials, where electrical transport would be more effici...

Feb 17, 2023

Advancing the Next Generation of Solar Fuels with Copper “Nanograins”

AZoNano - Nanotechnology Websites

Since the 1970s, scientists have known that copper has a special ability to transform carbon dioxide into valuable chemicals and fuels. But for many years, scientists have struggled to understand how...

Feb 17, 2023

Facile and scalable production of a fuel-cell nanocatalyst for the hydrogen economy

NanoDaily - Scientific News Websites

Daejeon, South Korea (SPX) Feb 17, 2023 A fuel cell is an electric power generator that is capable of producing electricity from hydrogen gas while discharging only water as a waste product. It is hoped that this highly efficient clean energy s...

Feb 17, 2023

Nanoparticles drill holes at will in silicon

Nanowerk - Nanotechnology Websites

Industrially usable technique for producing porous silicon and glass opens up fresh perspectives for numerous applications.

Feb 17, 2023

The Future of Error Correction: Taking Advantage of Quantum Scrambling ",plain_text=" Researchers have discovered that complex random behaviors naturally emerge from even the simplest, chaotic dynamics in a quantum simulator. This illustration zooms into one such complex set of states within an apparently smooth quantum system. Credit: Adam Shaw/CaltechThe randomness in quantum machines helps confirm their accuracy.Quantum computers and other quantum systems experience information spreading and rapid scrambling, similar to the way dice become jumbled in a game of Boggle. This occurs as the system’s basic units, known as qubits (which are similar to classical computer bits but are quantum in nature), become entangled with one another. Entanglement is a quantum physics phenomenon where particles become connected and remain linked even though they are not in direct contact.These quantum systems mimic natural processes and offer scientists the opportunity to create innovative and unique materials with potential applications in medicine, computer electronics, and other industries. Although full-scale quantum computers are still far in the future, researchers are currently conducting experiments with quantum simulators, which are specially designed to solve specific problems, such as efficiently simulating high-temperature superconductors and other quantum materials. These machines also have the potential to solve complex optimization problems, such as preventing collisions in autonomous vehicle routing.One challenge in using these quantum machines is that they are very prone to errors, much more so than classical computers. It is also much harder to identify errors in these newer systems. “For the most part, quantum computers make a lot of mistakes,” says Adam Shaw, a Caltech graduate student in physics and one of two lead authors of a study in the journal Nature about a new method to verify the accuracy of quantum devices. “You cannot open the machine and look inside, and there is a huge amount of information being stored—too much for a classical computer to account for and verify.”In the Nature study, Shaw and co-lead author Joonhee Choi, a former postdoctoral scholar at Caltech who is now a professor at Stanford University, demonstrate a novel way to measure a quantum device’s accuracy, also known as fidelity. Both researchers work in the laboratory of Manuel Endres, a professor of physics at Caltech and a Rosenberg scholar. The key to their new strategy is randomness. The scientists have discovered and characterized a newfound type of randomness pertaining to the way information is scrambled in the quantum systems. But even though the quantum behavior is random, universal statistical patterns can be identified in the noise.“We are interested in better understanding what happens when the information is scrambled,” Choi says. “And by analyzing this behavior with statistics, we can look for deviations in the patterns that indicate errors have been made.”“We don’t want just a result from our quantum machines; we want a verified result,” Endres says. “Because of quantum chaos, a single microscopic error leads to a completely different macroscopic outcome, quite similar to the butterfly effect. This enables us to detect the error efficiently.”The researchers demonstrated their protocol on a quantum simulator with as many as 25 qubits. To find whether errors have occurred, they measured the behavior of the system down to the single qubit level thousands of times. By looking at how qubits evolved over time, the researchers could identify patterns in the seemingly random behavior and then look for deviations from what they expected. Ultimately, by finding errors, researchers will know how and when to fix them.“We can trace how information moves across a system with single qubit resolution,” Choi says. “The reason we can do this is that we also discovered that this randomness, which just happens naturally, is represented at the level of just one qubit. You can see the universal random pattern in the subparts of the system.”Shaw compares their work to measuring the choppiness of waves on a lake. “If a wind comes, you’ll get peaks and troughs on the lake, and while it may look random, one could identify a pattern to the randomness and track how the wind affects the water. We would be able to tell if the wind changes by analyzing how the pattern changes. Our new method similarly allows us to look for changes in the quantum system that would indicate errors.”Reference: “Preparing random states and benchmarking with many-body quantum chaos” by Joonhee Choi, Adam L. Shaw, Ivaylo S. Madjarov, Xin Xie, Ran Finkelstein, Jacob P. Covey, Jordan S. Cotler, Daniel K. Mark, Hsin-Yuan Huang, Anant Kale, Hannes Pichler, Fernando G. S. L. Brandão, Soonwon Choi and Manuel Endres, 18 January 2023, Nature.DOI: 10.1038/s41586-022-05442-1The study was funded, in part, by the U.S. National Science Foundation, the Defense Advanced Research Projects Agency, the Army Research Office, and the Department of Energy.

SciTechDaily - Scientific News Websites

The randomness in quantum machines helps confirm their accuracy. Quantum computers and other quantum systems experience information spreading and rapid scrambling, similar to the way...

Feb 17, 2023

Glassy eyes may help young crustaceans hide from predators in plain sight

Science News - Scientific News Websites

Nanospheres in the eye reflect light that matches the color of the surrounding water, possibly making the animals invisible to nearby predators.

Feb 16, 2023

How a record-breaking copper catalyst converts CO2 into liquid fuels

ScienceDaily - General News Websites

Researchers have made real-time movies of copper nanoparticles as they evolve to convert carbon dioxide and water into renewable fuels and chemicals. Their new insights could help advance the next generation of solar fuels.

Feb 16, 2023

From plastic waste to valuable nanomaterials: 'Flash Joule' technique efficiently turns would-be pollution into valuable nanomaterials

ScienceDaily - General News Websites

Scientists create carbon nanotubes and other hybrid nanomaterials out of plastic waste using an energy-efficient, low-cost, low-emissions process that could also be profitable.

Feb 16, 2023

Smooth sailing for electrons in graphene: Measuring fluid-like flow at nanometer resolution

Phys.org - Scientific News Websites

Physicists at the University of Wisconsin-Madison have directly measured the fluid-like flow of electrons in graphene at nanometer resolution for the first time. The results appear in the journal Science today.

Feb 16, 2023

Facile and scalable production of a fuel-cell nanocatalyst for the hydrogen economy

Phys.org - Scientific News Websites

A fuel cell is an electric power generator that is capable of producing electricity from hydrogen gas while discharging only water as a waste product. It is hoped that this highly efficient clean energy system will play a key role in the adoption ...

Feb 16, 2023