Spin Rectification Effect and Thermoelectric Contributions in the Spin Pumping Measurements

Bingfeng Miao, Nanjing University

11am ET, Friday, May 13, 2022

Spin pumping is a technique widely used to generate the pure spin current and characterize the spin-charge conversion in various systems. The reversing sign of the symmetric Lorentzian charge current with respect to opposite magnetic field is generally accepted as the key criterion to identify its pure spin current origin. However, the parasitic spin rectification and thermoelectric contributions therein can exhibit similar spurious signals, complicating and even misleading the analysis. In this talk, I would first discuss the rectified voltage due to the planar Hall effect, which could exhibit similar line-shape and magnetic field symmetry as the spin-to-charge conversion signal in certain geometry. The distribution of microwave magnetic field and induction current has strong influence on the obtained signal. I will then demonstrate a geometry where the spin-charge conversion and the rectified voltage can be readily distinguished with a straightforward symmetry analysis. Lastly, I will present a quantitative method to obtain the thermoelectric contributions in spin pumping signals.

References:

[1] K. He, J. Cheng, M. Yang, Y. H. Zhang, L. Q. Yu, Q. Liu, L. Sun, B. F. Miao*, C. M. Hu, and H. F. Ding, Phys. Rev. B 105.104406 (2022).

[2] J. Cheng, K. He, M. Yang, Q. Liu, R. Yu, L. Sun, J. Ding, B. F. Miao*, M. Wu, and H. F. Ding, Phys. Rev. B 103, 014415 (2021).