. 24/7 Space News .
TIME AND SPACE
Novel method to study quantum fluctuations in exotic phases of matter
by Staff Writers
Osaka, Japan (SPX) May 31, 2017


(a) Spin and orbital degrees of freedom of electron in a carbon nanotube quantum dot is shown by the straight blue arrows and circle purple arrows, respectively. We can control the number of electrons in the quantum dot one by one by the nearby gate electrode (not shown in the figure). (b) Because of the spin and orbital degrees of freedom, an SU(4) Kondo state is formed at zero magnetic field as shown in the bottom panel. At high magnetic field it evolves continuously to an SU(2) Kondo effect (top panel). Credit Osaka University

We encounter phase transitions in our everyday lives when we witness water freezing or boiling. Similarly, quantum systems at a temperature of absolute zero also experience phase transitions. The pressure or magnetic field applied to such systems can be adjusted so that these systems arrive at a tipping point between two phases. At this point quantum fluctuations, rather than temperature fluctuations, drive these transitions.

Many fascinating phenomena with promising technological applications in areas such as superconductivity are linked to quantum phase transitions, but the role of quantum fluctuations in such transitions remains unclear. While there have been many advances in understanding the behavior of individual particles such as protons, neutrons, and photons, the challenge of understanding systems containing many particles that strongly interact with one another has yet to be solved.

Now, an international research team led by a group at Osaka University has discovered a clear link between quantum fluctuations and the effective charge of current-carrying particles. This discovery will help researchers uncover how quantum fluctuations govern systems in which many particles interact.

One example of such a system is the interaction of electrons at extremely low temperatures. While low temperatures normally cause the resistance in a metal to drop, the resistance rises again at extremely low temperatures due to small magnetic impurities--this is referred to as the Kondo effect.

"We used a magnetic field to tune the Kondo state in a carbon nanotube, ensuring that the quantum fluctuations were the only variable in the system," study coauthor Kensuke Kobayashi says. "By directly monitoring the conductance and shot noise of the carbon nanotube, we were able to demonstrate a continuous crossover between Kondo states with different symmetries."

Using this novel approach, the researchers discovered a link between quantum fluctuations and the effective charge of current-carrying particles, e*. The discovery means that measurements of e* can be used to quantify quantum fluctuations.

"This is very exciting, as it paves the way for future investigations into the exact role of quantum fluctuations in quantum phase transitions," explains Professor Kobayashi. Understanding quantum phase transitions has the potential to enable many interesting applications in areas such as superconductivity, Mott insulators, and the fractional quantum Hall effect.

Research paper

TIME AND SPACE
The synchronized dance of skyrmion spins
Washington DC (SPX) May 31, 2017
In recent years, excitement has swirled around a type of quasi-particle called a skyrmion that arises as a collective behavior of a group of electrons. Because they're stable, only a few nanometers in size, and need just small electric currents to transport them, skyrmions hold potential as the basis for ultra-compact and energy-efficient information storage and processing devices in the future. ... read more

Related Links
Osaka University
Understanding Time and Space


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
Astronauts return after marathon ISS mission

From 2D to 3D, Space Station Microscope Gets an Upgrade

Studying Flame Behavior in Microgravity with a Solid "High-Five"

NASA honors Kennedy's space vision on 100th birthday

TIME AND SPACE
SpaceX blasts off cargo using recycled spaceship

Ariane 5 launches its heaviest telecom payload

Eutelsat signs new launch contract with Arianespace

Ariane 5 launches its first all-electric satellite

TIME AND SPACE
Halos discovered on Mars widen time frame for potential life

Curiosity Peels Back Layers on Ancient Martian Lake

Student-Made Mars Rover Concepts Lift Off

Illinois Company Among Hundreds Supporting NASA Mission to Mars

TIME AND SPACE
California Woman Charged for Trying to Hand Over Sensitive Space Tech to China

A cabin on the moon? China hones the lunar lifestyle

China tests 'Lunar Palace' as it eyes moon mission

China to conduct several manned space flights around 2020

TIME AND SPACE
Thomas Pesquet returns to Earth

Propose a course idea for the CU space minor

Leading Global Air And Space Law Group Joins Reed Smith

New Horizons for Alexander Gerst

TIME AND SPACE
When gold turns invisible

Mitsubishi Electric Completes New Satellite Component Production Facility

High pressure key to lighter, stronger metal alloys, Stanford scientists find

Northrop Grumman receives AESA radar contract

TIME AND SPACE
Giant Ringed Planet Likely Cause of Mysterious Eclipses

New Collaboration with Jodrell Bank Observatory for SETI

Viable Spores, DNA Fragments Discovery at ISS Justifies Biosphere's Expansion

Russia thinks microorganisms may be living outside the space station

TIME AND SPACE
A whole new Jupiter with first science results from Juno

First results from Juno show cyclones and massive magnetism

Jupiters complex transient auroras

NASA's Juno probe forces 'rethink' on Jupiter









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.