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Primeur weekly 2019-02-18

Focus

2018 - Another year on the Road to Exascale - Part III - Software and applications ...

EOSCpilot science demonstrators boost follow-up initiatives in federating European Open Science Cloud concept ...

Quantum computing

Questions in quantum computing: How to move electrons with light ...

Focus on Europe

Arm SVE Hackathon to focus on Arm Scalable Performance for HPC and ML ...

EuroHPC Summit Week 2019: PRACEdays19 Call for Contributions and Posters is open ...

PRACE Ada Lovelace Award nominations open ...

Middleware

Bright Computing selects XENON as an Asia Pacific Services Partner ...

Hardware

RIKEN issues call for proposals for the name of the post-K ...

Fujitsu receives order for massively parallel supercomputer system called Oakbridge-CX from the University of Tokyo ...

Cray reports 2018 full year and fourth quarter financial results ...

South African Weather Center doubles computing and triples storage system capacities with Cray ...

WekaIO Matrix cements its storage leadership with groundbreaking performance and latency results on SPEC SFS 2014 ...

NERSC tape archives make the move to Berkeley Lab's Shyh Wang Hall ...

NVIDIA announces financial results for fourth quarter and fiscal 2019 ...

Applications

CERIC-ERIC call for proposals is now open ...

CalTech researcher uses Blue Waters to model galactic atmospheres ...

Six research groups awarded new GLCPC allocations on Blue Waters supercomputer ...

Visualizing biomedical breakthroughs in data ...

Theories describe dynamically disordered solid materials ...

Dark fiber lays groundwork for long-distance earthquake detection and groundwater mapping ...

Vanderbilt University Medical Center researchers, supercomputing effort reveal antibody secrets ...

ORNL teams with Los Alamos and EPB to demonstrate next-generation grid security tech ...

The Cloud

IBM Watson now available anywhere ...

Questions in quantum computing: How to move electrons with light


The Quantum Dynamics Unit traps a 2-D layer of electrons in liquid helium, held inside a sealed chamber and cooled to nearly absolute zero. Inside the chamber, a metal plate and spherical mirror on the top reflect microwave light (the red beam), and thus form a microwave cavity (resonator). The trapped microwaves interact with the electrons floating on the liquid helium.
12 Feb 2019 Okinawa - Tiny moving particles make up everything in our physical world - including modern electronics, whose function relies on the movement of negatively-charged electrons. Physicists strive to understand the forces that push these particles into motion, with the goal of harnessing their power in new technologies. Quantum computers, for instance, employ a fleet of precisely controlled electrons to take on goliath computational tasks. Recently, researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) demonstrated how a form of light, called microwaves, cuts in on the movement of electrons. The findings may help improve quantum computing.

Normal computers run on zeros and ones, and this binary code limits the volume and type of information the machines can process. Subatomic particles can exist in more than two discrete states, so quantum computers harness electrons to crunch complex data and perform functions at whiplash speed. To keep electrons in limbo, scientists capture the particles and expose them to forces that alter their behaviour.

In the new study, published December 18, 2018 inPhysical Review B, OIST researchers trapped electrons in a frigid, vacuum-sealed chamber and subjected them to microwaves. The particles and light altered each other's movement and exchanged energy, which suggests the sealed system could potentially be used to store quantum information - a microchip of the future.

"This is a small step towards a project that requires a lot more research", stated Jiabao Chen, first author of the paper and a graduate student in the OIST Quantum Dynamics Unit, led by Prof. Denis Konstantinov, "creating novel states of electrons for the purpose of quantum computing and storing quantum information."

Light, composed of fast, oscillating electric and magnetic fields can push around charged matter it meets in the environment. If light vibrates at the same frequency as electrons it encounters, the light and particles can exchange energy and information. When that occurs, the motion of the light and electrons is "coupled". If the energy exchange occurs more quickly than other light-matter interactions in the environment, the motion is "strongly coupled". Here, the scientists set out to achieve a strongly coupled state using microwaves.

"Achieving strong coupling is an important step towards quantum mechanical control over particles using light", stated Jiabao Chen. "This may be important if we want to generate some non-classical state of matter."

To observe strong coupling clearly, it helps to isolate electrons from misleading "signal noise" in their environment, which arises when electrons collide with nearby matter or interact with heat. Scientists have studied the impact of microwaves on electrons in semiconductor interfaces - where a semiconductor meets an insulator, thus confining the movement of electrons to one plane. But semiconductors contain impurities that impede the natural movement of electrons.

No material is completely devoid of defects, so the Quantum Dynamics Unit opts for an alternate solution - isolating their electrons in frigid vacuum-sealed chambers fitted with two metal mirrors that reflect microwaves.

The chambers, small cylindrical containers called cells, each contain a pool of liquid helium, kept at a temperature close to absolute zero. Helium remains liquid at this extreme temperature, but any impurities floating inside the substance freeze and cling to the sides of the cell. Electrons bind to the helium's surface, effectively forming a two-dimensional sheet. Researchers can then expose the waiting electrons to electromagnetic radiation, such as microwaves, by capturing the light between the two mirrors within the cell.

This relatively simple system revealed the influence of microwaves on the rotation of electrons - an effect that had been invisible in semiconductors.

"In our set-up, we can determine the course of physical phenomenon more clearly", stated Dr. Oleksiy Zadorozhko, an author on the paper and postdoctoral scholar in the Quantum Dynamics Unit. "We found that microwaves had significant influence on the movement on electrons."

The physicists described their findings mathematically and found that fluctuations in the speed, location or overall charge of individual electrons had little influence over the strong coupling effects. Instead, the average movement of particles and microwaves, en masse, appeared to trigger an exchange of energy and information between them.

The researchers hope that, in the future, the liquid helium system will grant them precise control over electrons, thereby allowing them to read, write and process quantum information similar to how we store standard data on a hard drive. With enhanced understanding of this system, the Quantum Dynamics Unit aims to improve upon the industry standard for qubits - bits of quantum information. Their efforts may lead to the development of faster, more powerful quantum technologies.

The paper titled " Strong coupling of a two-dimensional electron ensemble to a single-mode cavity resonator " is authored by Jiabao Chen, A. A. Zadorozhko, and D. Konstantinov, Quantum Dynamics Unit, Okinawa Institute of Science and Technology Graduate University - https://doi.org/10.1103/PhysRevB.98.235418.
Source: Okinawa Institute of Science and Technology Graduate University - OIST

Back to Table of contents

Primeur weekly 2019-02-18

Focus

2018 - Another year on the Road to Exascale - Part III - Software and applications ...

EOSCpilot science demonstrators boost follow-up initiatives in federating European Open Science Cloud concept ...

Quantum computing

Questions in quantum computing: How to move electrons with light ...

Focus on Europe

Arm SVE Hackathon to focus on Arm Scalable Performance for HPC and ML ...

EuroHPC Summit Week 2019: PRACEdays19 Call for Contributions and Posters is open ...

PRACE Ada Lovelace Award nominations open ...

Middleware

Bright Computing selects XENON as an Asia Pacific Services Partner ...

Hardware

RIKEN issues call for proposals for the name of the post-K ...

Fujitsu receives order for massively parallel supercomputer system called Oakbridge-CX from the University of Tokyo ...

Cray reports 2018 full year and fourth quarter financial results ...

South African Weather Center doubles computing and triples storage system capacities with Cray ...

WekaIO Matrix cements its storage leadership with groundbreaking performance and latency results on SPEC SFS 2014 ...

NERSC tape archives make the move to Berkeley Lab's Shyh Wang Hall ...

NVIDIA announces financial results for fourth quarter and fiscal 2019 ...

Applications

CERIC-ERIC call for proposals is now open ...

CalTech researcher uses Blue Waters to model galactic atmospheres ...

Six research groups awarded new GLCPC allocations on Blue Waters supercomputer ...

Visualizing biomedical breakthroughs in data ...

Theories describe dynamically disordered solid materials ...

Dark fiber lays groundwork for long-distance earthquake detection and groundwater mapping ...

Vanderbilt University Medical Center researchers, supercomputing effort reveal antibody secrets ...

ORNL teams with Los Alamos and EPB to demonstrate next-generation grid security tech ...

The Cloud

IBM Watson now available anywhere ...