Enhancement of 2D Topological Semimetal Transport Properties by Current Annealing

Authors

A. Fereidouni, University of Arkansas, FayettevilleFollow
M. H. Doha, University of Arkansas, FayettevilleFollow
K. Pandey, University of Arkansas, FayettevilleFollow
R. Basnet, University of Arkansas, FayettevilleFollow
J. Hu, University of Arkansas, Fayetteville
H. O. H. Churchill, University of Arkansas, Fayetteville

Document Type

Article

Publication Date

9-2022

Keywords

Electronic transport; Fermi surface; Quantum oscillations; Contact impedance; Annealing; Raman spectroscopy; Semimetals

Abstract

Observation of intrinsic quantum transport properties of two-dimensional (2D) topological semimetals can be challenging due to suppression of high mobility caused by extrinsic factors introduced during fabrication. We demonstrate current annealing as a method to substantially improve electronic transport properties of 2D topological semimetal flakes. Contact resistance and resistivity were improved by factors up to 2×10⁶ and 2×10⁴⁠, respectively, in devices based on exfoliated flakes of two topological semimetals, ZrSiSe and BaMnSb₂. Using this method, carrier mobility in ZrSiSe was improved by a factor of 3800, resulting in observation of record-high mobility for exfoliated ZrSiSe. Quantum oscillations in annealed ZrSiSe appeared at magnetic fields as low as 5 T, and magnetoresistance increased by a factor of 10⁴. We argue that a thermal process underlies this improvement. Finally, Raman spectroscopy and analysis of quantum oscillations in ZrSiSe indicate that the phonon modes and Fermi surface area are unchanged by current annealing.

Citation

Fereidouni, A., Doha, M. H., Pandey, K., Basnet, R., Hu, J., & Churchill, H. O. (2022). Enhancement of 2D Topological Semimetal Transport Properties by Current Annealing. Applied Physics Letters, 121 (11), 113101. https://doi.org/10.1063/5.0102933

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