7 November 2017

New magnetic topological semimetal has energy-saving potential

(Left) Out-of-plane magnetoresistivity as a function of magnetic field, showing strong  quantum oscillations. (Right) Out-of-plane magnetoresistivity measured up to 65T in pulsed magnetic fields. (Left) Out-of-plane magnetoresistivity as a function of magnetic field, showing strong quantum oscillations. (Right) Out-of-plane magnetoresistivity measured up to 65T in pulsed magnetic fields.

Researchers discover that Sr1-yMn1-zSb2 (y,z < 0.1) is a so-called Weyl material that holds great promise for building devices that require far less power.

First, some background

A fundamental building block of the standard model for particle physics is the Weyl fermion. First postulated in 1929, it has been sought after by high-energy physicists for decades without success. Recent breakthroughs in condensed matter physics have allowed the observation of Weyl fermions as quasiparticles in crystalline materials.

What did scientists discover?

THE TOOLS THEY USED

This research was conducted in the 65 Tesla Multi-Shot Magnet at the MagLab's Pulsed Field Facility and the 35 Tesla, 32 mm Bore Magnet at the DC Field Facility.

Working in high magnetic fields, scientists have shown Sr1-yMn1-zSb2 (y,z < 0.1) to be a Weyl material.

This new magnetic material displays electronic charge carriers that have almost no mass in any of the three directions, resulting in much faster than normal electron movement through the material. The magnetism brings with it an important symmetry-breaking property — time reversal symmetry (TRS) breaking. The combination of relativistic electron behavior and TRS breaking has been predicted to cause even more unusual behavior: the much sought-after magnetic Weyl semimetal phase.

Why is this important?

The recent discoveries of topological materials hold great promise for reducing energy consumption in electronics because they constitute a new class of quantum materials in which the current-carrying electrons can act as if they have no mass, similar to the properties of photons.

Amazingly, these electronic states are robust and immune to defects and disorder because they are protected from scattering by symmetry. This scattering is what leads to energy losses in conventional conductors like copper. The result is expected to be an increase in energy-saving efficiencies in electronic devices.

Who did the research?

J. Y. Liu1, J. Hu1, Q. Zhang2,3, D. Graf4, H. Cao3, S. Radmanesh5, D. Adams5, Y. Zhu1, G. Cheng1,6, X. Liu1,W. Phelan2, J.Wei1, M. Jaime7, F. Balakirev7, D. Tennant3, J. DiTusa2, I. Chiorescu4,8, L. Spinu5 and Z. Q. Mao1

1Tulane Univ., New Orleans, LA; 2LSU, Baton Rouge, LA; 3ORNL, Oak Ridge, TN; 4National MagLab, Tallahassee, FL; 5Univ. New Orleans, New Orleans, LA; 6CAS, Shangai, China; 7LANL, Los Alamos, NM; 8FSU-TLH, FL.

Why did they need the MagLab?

The high magnetic fields provided by the MagLab allowed the researchers to determine that the electrons in this material move at nearly-relativistic speeds by using the observation of quantum oscillations to determine the effective mass of the charge carriers.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490); Z.Q. Mao (NSF DMR-1205469)


For more information, contact Tim Murphy.

Details

  • Research Area: Magnetism and Magnetic Materials, Quantum Fluids and Solids, Topological Matter
  • Research Initiatives: Energy,Materials
  • Facility / Program: DC Field, Pulsed Field
  • Year: 2017
Last modified on 7 November 2017