Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Natural 3D Counterpart to Graphene Discovered: Researchers at Berkeley Lab’s Advanced Light Source Find New Form of Quantum Matter

A topological Dirac semi-metal state is realized at the critical point in the phase transition from a normal insulator to a topological insulator. The + and – signs denote the even and odd parity of the energy bands.
A topological Dirac semi-metal state is realized at the critical point in the phase transition from a normal insulator to a topological insulator. The + and – signs denote the even and odd parity of the energy bands.

Abstract:
The discovery of what is essentially a 3D version of graphene - the 2D sheets of carbon through which electrons race at many times the speed at which they move through silicon - promises exciting new things to come for the high-tech industry, including much faster transistors and far more compact hard drives. A collaboration of researchers at the U.S Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has discovered that sodium bismuthate can exist as a form of quantum matter called a three-dimensional topological Dirac semi-metal (3DTDS). This is the first experimental confirmation of 3D Dirac fermions in the interior or bulk of a material, a novel state that was only recently proposed by theorists.

Natural 3D Counterpart to Graphene Discovered: Researchers at Berkeley Lab’s Advanced Light Source Find New Form of Quantum Matter

Berkeley, CA | Posted on January 16th, 2014

"A 3DTDS is a natural three-dimensional counterpart to graphene with similar or even better electron mobility and velocity," says Yulin Chen, a physicist with Berkeley Lab's Advanced Light Source (ALS) when he initiated the study that led to this discovery, and now with the University of Oxford. "Because of its 3D Dirac fermions in the bulk, a 3DTDS also features intriguing non-saturating linear magnetoresistance that can be orders of magnitude higher than the materials now used in hard drives, and it opens the door to more efficient optical sensors."

Chen is the corresponding author of a paper in Science reporting the discovery. The paper is titled "Discovery of a Three-dimensional Topological Dirac Semimetal, Na3Bi." Co-authors were Zhongkai Liu, Bo Zhou, Yi Zhang, Zhijun Wang, Hongming Weng, Dharmalingam Prabhakaran, Sung-Kwan Mo, Zhi-Xun Shen, Zhong Fang, Xi Dai and Zahid Hussain.

Two of the most exciting new materials in the world of high technology today are graphene and topological insulators, crystalline materials that are electrically insulating in the bulk but conducting on the surface. Both feature 2D Dirac fermions (fermions that aren't their own antiparticle), which give rise to extraordinary and highly coveted physical properties. Topological insulators also possess a unique electronic structure, in which bulk electrons behave like those in an insulator while surface electrons behave like those in graphene.

"The swift development of graphene and topological insulators has raised questions as to whether there are 3D counterparts and other materials with unusual topology in their electronic structure," says Chen. "Our discovery answers both questions. In the sodium bismuthate we studied, the bulk conduction and valence bands touch only at discrete points and disperse linearly along all three momentum directions to form bulk 3D Dirac fermions. Furthermore, the topology of a 3DTSD electronic structure is also as unique as those of topological insulators."

The discovery was made at the Advanced Light Source (ALS), a DOE national user facility housed at Berkeley Lab, using beamline 10.0.1, which is optimized for electron structure studies. The collaborating research team first developed a special procedure to properly synthesize and transport the sodium bismuthate, a semi-metal compound identified as a strong 3DTDS candidate by co-authors Fang and Dai, theorists with the Chinese Academy of Sciences.

At ALS beamline 10.0.1, the collaborators determined the electronic structure of their material using Angle-Resolved Photoemission Spectroscopy (ARPES), in which x-rays striking a material surface or interface cause the photoemission of electrons at angles and kinetic energies that can be measured to obtain a detailed electronic spectrum.

"ALS beamline 10.0.1 is perfect for exploring new materials, as it has a unique capability whereby the analyzer is moved rather than the sample for the ARPES measurement scans," Chen says. "This made our work much easier as the cleaved sample surface of our material sometimes has multiple facets, which makes the rotating-sample measurement schemes typically employed for ARPES measurements difficult to carry out."

Sodium bismuthate is too unstable to be used in devices without proper packaging, but it triggers the exploration for the development of other 3DTDS materials more suitable for everyday devices, a search that is already underway. Sodium bismuthate can also be used to demonstrate potential applications of 3DTDS systems, which offer some distinct advantages over graphene.

"A 3DTDS system could provide a significant improvement in efficiency in many applications over graphene because of its 3D volume," Chen says. "Also, preparing large-size atomically thin single domain graphene films is still a challenge. It could be easier to fabricate graphene-type devices for a wider range of applications from 3DTDS systems."

In addition, Chen says, a 3DTDS system also opens the door to other novel physical properties, such as giant diamagnetism that diverges when energy approaches the 3D Dirac point, quantum magnetoresistance in the bulk, unique Landau level structures under strong magnetic fields, and oscillating quantum spin Hall effects. All of these novel properties can be a boon for future electronic technologies. Future 3DTDS systems can also serve as an ideal platform for applications in spintronics.

This research was supported by the DOE Office of Science and by the National Science Foundation of China.

####

About Berkeley Lab
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The Advanced Light Source is a third-generation synchrotron light source producing light in the x-ray region of the spectrum that is a billion times brighter than the sun. A DOE national user facility, the ALS attracts scientists from around the world and supports its users in doing outstanding science in a safe environment. For more information visit http://www.als.lbl.gov/.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

Copyright © Berkeley Lab

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

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Arrowhead Pharmaceuticals to Webcast Fiscal 2017 Third Quarter Results July 27th, 2017

Living computers: RNA circuits transform cells into nanodevices July 27th, 2017

Laboratories

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

Studying Argon Gas Trapped in Two-Dimensional Array of Tiny "Cages": Understanding how individual atoms enter and exit the nanoporous frameworks could help scientists design new materials for gas separation and nuclear waste remediation July 17th, 2017

News laser design offers more inexpensive multi-color output: Design can control color, intensity of light by varying cavity architecture July 11th, 2017

Imaging

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Phenom-World Launches Phenom Pro and ProX Generation 5 SEMs at Microscopy & Microanalysis Conference USA: The excellent performance in a wide range of applications offers a serious alternative to floor model SEMs July 26th, 2017

Coupling a nano-trumpet with a quantum dot enables precise position determination July 14th, 2017

Graphene/ Graphite

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Superconductivity

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

Physics

The first light atomic nucleus with a second face July 20th, 2017

Govt.-Legislation/Regulation/Funding/Policy

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Ultracold molecules hold promise for quantum computing: New approach yields long-lasting configurations that could provide long-sought “qubit” material July 27th, 2017

Spintronics

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

First experimental proof of a 70 year old physics theory: First observation of magnetic phase transition in 2-D materials, as predicted by the Nobel winner Onsager in 1943 January 6th, 2017

Investigations of the skyrmion Hall effect reveal surprising results: One step further towards the application of skyrmions in spintronic devices December 28th, 2016

Electron highway inside crystal December 12th, 2016

Chip Technology

Atomic discovery opens door to greener, faster, smaller electronic circuitry: Scientists find way to correct communication pathways in silicon chips, making them perfect July 27th, 2017

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

First Capacitive Transducer with 13nm Gap July 27th, 2017

Living computers: RNA circuits transform cells into nanodevices July 27th, 2017

Memory Technology

Liquid electrolyte contacts for advanced characterization of resistive switching memories July 26th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Pulses of electrons manipulate nanomagnets and store information: Scientists use electron pulses to create and manipulate nanoscale magnetic excitations that can store data July 21st, 2017

A firefly's flash inspires new nanolaser light July 18th, 2017

Discoveries

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

First Capacitive Transducer with 13nm Gap July 27th, 2017

Materials/Metamaterials

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Regulation of two-dimensional nanomaterials: New driving force for lithium-ion batteries July 26th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Announcements

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

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

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Ultracold molecules hold promise for quantum computing: New approach yields long-lasting configurations that could provide long-sought “qubit” material July 27th, 2017

Atomic discovery opens door to greener, faster, smaller electronic circuitry: Scientists find way to correct communication pathways in silicon chips, making them perfect July 27th, 2017

Tools

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Phenom-World Launches Phenom Pro and ProX Generation 5 SEMs at Microscopy & Microanalysis Conference USA: The excellent performance in a wide range of applications offers a serious alternative to floor model SEMs July 26th, 2017

The School of Materials at the University of Manchester utilise Deben’s mechanical stages to characterise structure and behaviour at the micro- and nano- scale July 25th, 2017

Scientists announce the quest for high-index materials: All-dielectric nanophotonics: The quest for better materials and fabrication techniques July 22nd, 2017

Industrial

3-D-printed jars in ball-milling experiments June 29th, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Alloying materials of different structures offers new tool for controlling properties June 19th, 2017

Carbodeon demonstrates NanoDiamond nickel coatings with enhanced tribological properties June 7th, 2017

Research partnerships

High-speed FM-AFM and simulation reveal atomistic dissolution processes of calcite in water July 28th, 2017

Atomic movies may help explain why perovskite solar cells are more efficient: SLAC's ultrafast 'electron camera' captures surprising atomic motions in these next-generation materials July 28th, 2017

Triple-layer catalyst does double duty: Rice, University of Houston produce robust catalyst to split water into hydrogen, oxygen July 28th, 2017

Strange electrons break the crystal symmetry of high-temperature superconductors: Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature superconductors July 27th, 2017

Quantum nanoscience

Ultracold molecules hold promise for quantum computing: New approach yields long-lasting configurations that could provide long-sought “qubit” material July 27th, 2017

Carbon displays quantum effects July 13th, 2017

Physicists make quantum leap in understanding life's nanoscale machinery June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project