Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co2MnGa at room temperature

Han X, Markou A, Stensberg J, Sun Y, Felser C, Wu L (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Physical Review B American Physical Society

Book Volume: 105

Article Number: 174406

Journal Issue: 17

DOI: 10.1103/PhysRevB.105.174406

Abstract

We report measurement of terahertz anomalous Hall conductivity and Faraday rotation in the magnetic Weyl semimetal Co2MnGa thin films as a function of the magnetic field, temperature, and thickness, using time-domain terahertz spectroscopy. The terahertz conductivity shows a thickness-independent anomalous Hall conductivity of around 600 ω-1cm-1 at room temperature, and it is also frequency-independent from 0.2-1.5 THz. The magnitude of the longitudinal and Hall conductivities, the weak spin-orbit coupling, and the very close positioning of Weyl points to the chemical potential all satisfy the criteria for intrinsic anomalous Hall conductivity. First-principles calculation also supports the frequency-independent intrinsic anomalous Hall conductivity at low frequency. We also find a thickness-independent Faraday rotation of 59 (±6) mrad at room temperature, which comes from the intrinsic Berry curvature contribution. In the thinnest 20 nm sample, the Faraday rotation divided by the sample thickness reaches around 3 mrad/nm due to Berry curvature, and is the largest reported at room temperature. The giant Verdet constant of the order of 106 rad m-1 T-1 at room temperature and the large Hall angle around 8.5% from 0.2-1.5 THz indicate that Co2MnGa is promising for THz spintronics at room temperature.

Involved external institutions

Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) University of Pennsylvania US United States (USA) (US)

How to cite

APA:

Han, X., Markou, A., Stensberg, J., Sun, Y., Felser, C., & Wu, L. (2022). Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co2MnGa at room temperature. Physical Review B, 105(17). https://doi.org/10.1103/PhysRevB.105.174406

MLA:

Han, Xingyue, et al. "Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co2MnGa at room temperature." Physical Review B 105.17 (2022).

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