Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The quantum middle man

06.07.2015

Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have identified a system that could store quantum information for longer times, which is critical for the future of quantum computing. This study was recently published in Physical Review Letters.

Quantum computing -- which aims to use particles on the atomic scale to make calculations and store the results -- has the potential to solve some key problems much faster than current computers.


A crystal made of manganese and other elements that provides a strong hyperfine interaction between the nucleus and electrons is just a few millimeters wide. It is shown next to a 100 Yen coin for scale.

Credit: OIST

To make quantum computing a reality, scientists must find a system that remains stable long enough to make the calculations. While this is an extremely short time frame, only thousandths of a second, the particles involved are so small that they are easily influenced by their surroundings. If the motion of the particles is disturbed, even a little, it throws off the whole calculation.

Nuclei are promising contenders for quantum memory because they are not easily influenced by their surroundings. However, that also makes them extremely difficult to manipulate. Many quantum physicists have tried with little success.

"In usual materials it is very difficult to control nuclei directly," said Prof. Denis Konstantinov, who runs the Quantum Dynamics Unit at OIST.

Instead of trying control the nucleus directly, the researchers focused on a "middle man" of sorts - the electrons orbiting the nucleus.

The nucleus has a tiny internal magnet, called a "magnetic moment," and the electrons orbiting around it also have magnetic moments that are about 1,000 times larger. Those magnets interact with each other, which is called the "hyperfine interaction."

The hyperfine interaction is stronger in some materials than others. The researchers found that a crystal made of manganese and some other elements has a strong hyperfine interaction. This enabled them to manipulate the nuclei by first targeting the electrons.

Information in quantum computing is conveyed by photons, which are individual particles of light, which also make up other nonvisible electromagnetic waves, such as ultraviolet and microwaves. The information transmitted is actually the quantum state of the photon. The quantum state of the photon needs to be transferred to another particle so it will last long enough for the computation to take place.

In this experiment, the researchers beamed microwaves through a manganese carbonate crystal. The magnetic field of the microwaves interacted with the magnetic moments of the electrons that are orbiting around the nuclei of the manganese atoms. The electrons' movements started to change, which in turn altered the movement of the nuclei because they are connected by the hyperfine interaction. The quantum state of the microwave photon was transferred to the nuclei when the nuclei's internal magnets flipped to point in the opposite direction.

This all has to happen very quickly before the quantum state of the photon changes. To transmit the information and flip the nuclei fast enough, there has to be a strong connection between the microwaves and nuclei via the electrons.

"To our knowledge, our experiment is the first demonstration of the strong coupling between microwave photons and nuclear spins," said Leonid Abdurakhimov, a post-doctoral scholar at OIST and first author of the paper.

Next, the team plans to cool down the system to nearly -273 C, or -500 F, to see if they can strengthen the connection and extend the time information can be stored by minimizing temperature fluctuations.

"We are making the first and important steps towards using an ensemble of nuclear spins for quantum memory," Konstantinov said. "We now have a whole class of materials that can be used for this purpose. Future experiments promise to be quite exciting."

Media Contact

Kaoru Natori
kaoru.natori@oist.jp
81-989-662-389

 @oistedu

http://www.oist.jp/ 

Kaoru Natori | EurekAlert!

More articles from Physics and Astronomy:

nachricht Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich

nachricht Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>