Direct evidence of terahertz emission arising from anomalous Hall effect

Venkatesh Mottamchetty; Parul Rani; Rimantas Brucas; Anders Rydberg; Peter Svedlindh; Rahul Gupta

doi:10.1038/s41598-023-33143-w

Direct evidence of terahertz emission arising from anomalous Hall effect

Sci Rep. 2023 Apr 12;13(1):5988. doi: 10.1038/s41598-023-33143-w.

Authors

Venkatesh Mottamchetty¹, Parul Rani², Rimantas Brucas¹, Anders Rydberg^{1

2}, Peter Svedlindh³, Rahul Gupta^{4

5}

Affiliations

¹ Department of Materials Science and Engineering, Uppsala University, Box 35, 751 03, Uppsala, Sweden.
² Department of Physics and Astronomy, Uppsala University, Box 516, 75120, Uppsala, Sweden.
³ Department of Materials Science and Engineering, Uppsala University, Box 35, 751 03, Uppsala, Sweden. peter.svedlindh@angstrom.uu.se.
⁴ Department of Materials Science and Engineering, Uppsala University, Box 35, 751 03, Uppsala, Sweden. rahul.gupta@angstrom.uu.se.
⁵ Department of Physics and Astronomy, Uppsala University, Box 516, 75120, Uppsala, Sweden. rahul.gupta@angstrom.uu.se.

Abstract

A detailed understanding of the different mechanisms being responsible for terahertz (THz) emission in ferromagnetic (FM) materials will aid in designing efficient THz emitters. In this report, we present direct evidence of THz emission from single layer Co[Formula: see text]Fe[Formula: see text]B[Formula: see text] (CoFeB) FM thin films. The dominant mechanism being responsible for the THz emission is the anomalous Hall effect (AHE), which is an effect of a net backflow current in the FM layer created by the spin polarized current reflected at the interfaces of the FM layer. The THz emission from the AHE-based CoFeB emitter is optimized by varying its thickness, orientation, and pump fluence of the laser beam. Results from electrical transport measurements show that skew scattering of charge carriers is responsible for the THz emission in the CoFeB AHE-based THz emitter.

Abstract

Grants and funding