Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Yale-NUS scientist and collaborators solve open theoretical problem on electron interactions

The open problem was what controlled the velocity of the electron liquid (shown as a wavy waterfront). The findings show that it is the frozen antiferromagnetism on the honeycomb lattice that sets this velocity by slowing it down as the two interact.

CREDIT
Yale-NUS College
The open problem was what controlled the velocity of the electron liquid (shown as a wavy waterfront). The findings show that it is the frozen antiferromagnetism on the honeycomb lattice that sets this velocity by slowing it down as the two interact. CREDIT Yale-NUS College

Abstract:
Yale-NUS Associate Professor of Science (Physics) Shaffique Adam is the lead author for a recent work that describes a model for electron interaction in Dirac materials, a class of materials that includes graphene and topological insulators, solving a 65-year-old open theoretical problem in the process. The discovery will help scientists better understand electron interaction in new materials, paving the way for developing advanced electronics such as faster processors. The work was published in the peer-reviewed academic journal Science on 10 August 2018.

Yale-NUS scientist and collaborators solve open theoretical problem on electron interactions

Singapore | Posted on August 10th, 2018

Electron behaviour is governed by two major theories - the Coulomb's law and the Fermi liquid theory. According to Fermi liquid theory, electrons in a conductive material behave like a liquid - their "flow" through a material is what causes electricity. For Dirac fermions, the Fermi liquid theory breaks down if the Coulomb force between the electrons crosses a certain threshold: the electrons "freeze" into a more rigid pattern which inhibits the "flow" of electrons, causing the material to become non-conductive.

For more than 65 years, this problem was relegated to a mathematical curiosity, because Dirac materials where the Coulomb threshold was reached had never been made. Today, however, we routinely make use of quantum materials for applications in technology, such as transistors in processors, where the electrons are engineered to have desired properties, including those which push the Coulomb force past this threshold. But the effects of strong electron-electron interaction can only be seen in very clean samples.

In the work immediately following his PhD, Assoc Prof Adam proposed a model to describe experimentally available Dirac materials that were "very dirty" (contains a lot of impurities). However, in the years that followed, newer and cleaner materials have been made, and this previous theory no longer worked.

In this latest work titled, "The role of electron-electron interactions in two-dimensional Dirac fermions", Assoc Prof Adam and his research team have developed a model which explains electron interactions past the Coulomb threshold in all Dirac materials by using a combination of numerical and analytical techniques.

In this research, the team designed a method to study the evolution of physical observables in a controllable manner and used it to address the competing effects of short-range and long-range parts in models of the Coulomb interaction. The researchers discovered that the velocity of electrons (the "flow" speed) in a material could decrease if the short-range interaction that favoured the insulating, "frozen" state dominated. However, the velocity of electrons could be enhanced by the long-range component that favoured the conducting, "liquid" state. With this discovery, scientists can better understand long-range interactions of electrons non-perturbatively - something that previous theories were not able to explain - and serves as useful predictors for experiments exploring the long-range-interaction divergence in Dirac electrons when they transition between conducting to insulating phases.

This improved understanding in the evolution of the electron velocity during the phase transition paves the way to help scientists develop low heat dissipation devices for electronics. Assoc Prof Adam explains, "The higher the electron velocity, the faster transistors can be switched on and off. However, this faster processor performance comes at the price of increased power leakage, which produces extra heat, and this heat will counteract the performance increase granted by the faster switching. Our findings on electron velocity behaviour will help scientists engineer devices that are capable of faster switching but low power leakage."

Assoc Prof Adam adds, "Because the mechanism in our new model harnesses the Coulomb force, it would cost less energy per switch compared to mechanisms available currently. Understanding and applying our new model could potentially usher in a new generation of technology."

###

The team comprises researchers from the Centre for Advanced 2D Materials (CA2DM) and the Department of Physics at the National University of Singapore (NUS), at which Assoc Prof Adam also holds joint appointments, as well as researchers from Nanyang Technological University in Singapore, Simon Fraser University in Canada and Universität Würzburg in Germany.

The work was supported by the Singapore National Research Foundation (NRF-NRFF2012-01), Deutsche Forschungsgemeinschaft (SFB 1170 ToCoTronics, project C01), NSERC of Canada, and Singapore Ministry of Education.

(MOE2014-T2-1-112 and MOE2017-T2-1-130).

####

For more information, please click here

Contacts:
Jeannie Tay

65-660-14901

Copyright © Yale University and National University of Singapore

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Synopsys and GLOBALFOUNDRIES Collaborate to Develop Industry’s First Automotive Grade 1 IP for 22FDX Process: Synopsys’ Portfolio of DesignWare Foundation, Analog, and Interface IP Accelerate ISO 26262 Qualification for ADAS, Powertrain, 5G, and Radar Automotive SoCs February 22nd, 2019

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

Physics

Exotic spiraling electrons discovered by physicists: Rutgers-led research could lead to advances in lighting and solar cells February 18th, 2019

Sound and light trapped by disorder February 8th, 2019

Breaching the horizons: Universal spreading laws confirmed: A novel toolbox developed to implement ultrafast simulations of quantum transport allowed to achieve unprecedented limits in the understanding of wave spreading mechanisms February 4th, 2019

TOCHA will take a topological approach to the next generation of electronic, photonic and phononic devices January 31st, 2019

Govt.-Legislation/Regulation/Funding/Policy

NRL, AFRL develop direct-write quantum calligraphy in monolayer semiconductors February 15th, 2019

Researchers create ultra-lightweight ceramic material that withstands extreme temperatures: UCLA-led team develops highly durable aerogel that could ultimately be an upgrade for insulation on spacecraft February 15th, 2019

Sensitive sensor detects Down syndrome DNA February 14th, 2019

Laser-induced graphene gets tough, with help: Rice University lab combines conductive foam with other materials for capable new composites February 12th, 2019

Possible Futures

Synopsys and GLOBALFOUNDRIES Collaborate to Develop Industry’s First Automotive Grade 1 IP for 22FDX Process: Synopsys’ Portfolio of DesignWare Foundation, Analog, and Interface IP Accelerate ISO 26262 Qualification for ADAS, Powertrain, 5G, and Radar Automotive SoCs February 22nd, 2019

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

Discoveries

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

High-speed surveillance in solar cells catches recombination red-handed: Researchers at Osaka University introduce a new time-resolved microscopy method that allows them to monitor the trajectories of fast-moving charged particles at unprecedented rates February 21st, 2019

Materials/Metamaterials

Super-light, super-insulating ceramic aerogel keeps the hottest temperatures at bay February 17th, 2019

Laser-induced graphene gets tough, with help: Rice University lab combines conductive foam with other materials for capable new composites February 12th, 2019

Using artificial intelligence to engineer materials' properties: New system of 'strain engineering' can change a material's optical, electrical, and thermal properties February 11th, 2019

Sound and light trapped by disorder February 8th, 2019

Announcements

Synopsys and GLOBALFOUNDRIES Collaborate to Develop Industry’s First Automotive Grade 1 IP for 22FDX Process: Synopsys’ Portfolio of DesignWare Foundation, Analog, and Interface IP Accelerate ISO 26262 Qualification for ADAS, Powertrain, 5G, and Radar Automotive SoCs February 22nd, 2019

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

High-speed surveillance in solar cells catches recombination red-handed: Researchers at Osaka University introduce a new time-resolved microscopy method that allows them to monitor the trajectories of fast-moving charged particles at unprecedented rates February 21st, 2019

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

Nominations invited for $250,000 Kabiller Prize — the world’s largest monetary award for achievement in nanomedicine: An additional $10,000 award will honor a young investigator in nanoscience, nanomedicine February 7th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

Scientists program proteins to pair exactly: Technique paves the way for the creation of protein nanomachines and for the engineering of new cell functions December 21st, 2018

Strem Chemicals, Inc., Receives National Performance Improvement Honor: Company Recognized for Stakeholder Communications December 20th, 2018

Research partnerships

Synopsys and GLOBALFOUNDRIES Collaborate to Develop Industry’s First Automotive Grade 1 IP for 22FDX Process: Synopsys’ Portfolio of DesignWare Foundation, Analog, and Interface IP Accelerate ISO 26262 Qualification for ADAS, Powertrain, 5G, and Radar Automotive SoCs February 22nd, 2019

CEA-Leti & Stanford Target Edge-AI Apps with Breakthrough Memory Cell: Paper at ISSCC 2019 Presents Proof-of-Concept Multi-Bit Chip That Overcomes NVM’s Read/Write, Latency and Integration Challenges February 20th, 2019

Exotic spiraling electrons discovered by physicists: Rutgers-led research could lead to advances in lighting and solar cells February 18th, 2019

Laser-induced graphene gets tough, with help: Rice University lab combines conductive foam with other materials for capable new composites February 12th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project