Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electrons Move Like Light in Three-Dimensional Solid

24.04.2015

Tracking electronic motion in a graphene-like bulk material shows fast electrons in all dimensions.

The Science


Image courtesy of SLAC National Accelerator Laboratory

Artist’s conception highlighting key features of electron behavior in bulk sodium bismuth and cadmium arsenic. The interactions in the three-dimensional lattice lead to electrons that travel at a fixed velocity, independent of the electron’s energy state.

Electrons were observed to travel in a solid at an unusually high velocity, which remained the same independent of the electron energy. This anomalous light-like behavior is found in special two-dimensional materials, such as graphene, but is now realized in a three-dimensional bulk material. High-resolution angle-resolved electron spectroscopy, stimulated by synchrotron x-ray radiation, was used to substantiate the theoretically predicted exotic electron structure.

The Impact

A stable bulk material has been discovered that shows the same physics found in graphene, which illuminated the detailed interactions of electron’s orbital motion and its intrinsic magnetic orientation. The new material will be a test ground for theories on how electron interactions in solids shape exotic electron behavior, including the highest electron mobility in bulk materials.

Summary

Investigations of electronic behavior have expanded beyond familiar systems of metals, insulators, and semi-conductors into the realm of strongly interacting electrons, which exhibit exotic relationships between the allowed electron velocities and their energy states. A key feature for the new materials is behavior in which the electron velocity does not depend on its energy.

Such a relationship is a hallmark of photons, the energetic particles that make up a beam of light. This property is found in the new class of materials exhibiting a strong interaction between the electron trajectory and the electron spin alignment (called “spin-orbit coupling”). Two-dimensional versions of such systems (for example, grapheme) have been recently explored, but the systems are hard to work with because of their ultra-thin film nature.

This work establishes graphene-like electronic behavior in the bulk three-dimensional materials Na3Bi and Cd3As2 and explains their exceptionally high electronic mobility. The required advances in electron spectroscopy techniques, used to investigate the electronic structure, employed an energy tunable bright x-ray source and a high-resolution spectrometer.

Funding

Funded by DOE Office of Science, Basic Energy Sciences, including support for the Advanced Light Source. Researchers from foreign institutions were supported by the Engineering and Physical Sciences Research Council (UK), the National Science Foundation of China, the National Basic Research Program of China, the International Science and Technology Cooperation Program of China, the China Scholarship Council, and Defense Advanced Research Projects Agency (USA).

Publications

Z.K. Liu, B. Zhou, Y. Zhang, Z.J. Wang, H.M. Weng, D. Prabhakaran, S.K. Mo, Z.X. Shen, Z. Fang, X. Dai, Z. Hussain, Y.L. Chen, “Discovery of a three-dimensional topological Dirac semimetal, Na3Bi.” Science 343 (6173), 864–867 (2014). [DOI: 10.1126/science.1245085]

Z.K. Liu, J. Jiang, B. Zhou, Z.J. Wang, Y. Zhang, H.M. Weng, D. Prabhakaran, S.K. Mo, H. Peng, P. Dudin, T. Kim, M. Hoesch, Z. Fang, X. Dai, Z.X. Shen, D.L. Feng, Z. Hussain, Y.L. Chen, “A stable three-dimensional topological Dirac semimetal Cd3As2.” Nature Materials 13, 677–681 (2014). [DOI: 10.1038/nmat3990]

M. Neupane, S.Y. Xu, R. Sankar, N. Alidoust, G. Bian, C. Liu, I. Belopolski, T.R. Chang, H.T. Jeng, H. Lin, A. Bansil, F. Chou, M. Z. Hasan, “Observation of a three-dimensional topological Dirac semimetal phase in high-mobility Cd3As2.” Nature Communications 5, 3786 (2014). [DOI: 10.1038/ncomms4786]

Contact Information
Kristin Manke
kristin.manke@science.doe.gov

Kristin Manke | newswise
Further information:
http://www.science.doe.gov

Further reports about: Electrons Energy bulk material electronic behavior exotic interactions spectroscopy

More articles from Materials Sciences:

nachricht New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State

nachricht Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>