Exploring Topological Semimetals in High Magnetic Fields

Published March 23, 2020

Figure: (left) Raw quantum oscillation data as the applied magnetic field is tilted away from the a-axis. (right) Angular dependence of the three main orbits.

Topological semimetals are an exciting new area of research due to their number of predicted and unexpected quantum mechanical states. Understanding these materials may also lead to quantum devices that function at near room temperature.

What did scientists discover?

SrZnSb₂ was found to be a topological semimetal by using high magnetic fields to measure the shape of the Fermi surface and the strength of interactions between the electrons

Why is this important?

Topological semimetals and other topological materials comprise an exciting new area of research in condensed matter physics because they host a variety of quantum mechanical states which are observable on a macroscopic scale and are stable to high temperatures. Topological materials may be the key to leveraging quantum mechanics to design new devices with exciting functionalities that work at room temperature.

Who did the research?

Liu, J.¹, Liu, P.², Gordon, K.³, Emmanouilidou¹, E., Xing, J.¹, Graf, D.⁴, Chakoumakos, B.⁵, Wu, Y. ⁵, Cao, H. ⁵, Dessau, D. ³, Liu, Q.^2,6, Ni, N.¹

¹Univ. of California; ²Southern Univ. of Science and Tech., China; ³Univ. of Colorado, Boulder; ⁴National MagLab; ⁵Oak Ridge Nat'l Lab; ⁶Peng Cheng Laboratory, China

Why did they need the MagLab?

Measuring quantum oscillations allows scientists to measure how the electrons in a material interact with the crystalline structure and with each other. High magnetic fields are needed to fully explore the environment experienced by the conduction electrons in SrZnSb₂. As shown in Fig. (a), the oscillatory component of the signal grows exponentially with the magnetic field. The information gleaned from these measurements provides important insights into the source of the unique physics present in topological materials.