Ferromagnetic Resonance Spin Pumping and Electrical Spin Injection in Silicon-Based Metal-Oxide-Semiconductor Heterostructures

Y. Pu, P. M. Odenthal, R. Adur, J. Beardsley, A. G. Swartz, D. V. Pelekhov, M. E. Flatté, R. K. Kawakami, J. Pelz, P. C. Hammel, and E. Johnston-Halperin

Phys. Rev. Lett. 115, 246602 – Published 10 December 2015

Abstract

We present the measurement of ferromagnetic resonance (FMR-)driven spin pumping and three-terminal electrical spin injection within the same silicon-based device. Both effects manifest in a dc spin accumulation voltage $V_{s}$ that is suppressed as an applied field is rotated to the out-of-plane direction, i.e., the oblique Hanle geometry. Comparison of $V_{s}$ between these two spin injection mechanisms reveals an anomalously strong suppression of FMR-driven spin pumping with increasing out-of-plane field $H_{app}^{z}$ . We propose that the presence of the large ac component to the spin current generated by the spin pumping approach, expected to exceed the dc value by 2 orders of magnitude, is the origin of this discrepancy through its influence on the spin dynamics at the oxide-silicon interface. This convolution, wherein the dynamics of both the injector and the interface play a significant role in the spin accumulation, represents a new regime for spin injection that is not well described by existing models of either FMR-driven spin pumping or electrical spin injection.

Received 15 January 2015

DOI:https://doi.org/10.1103/PhysRevLett.115.246602

Authors & Affiliations

Y. Pu^1,*, P. M. Odenthal², R. Adur¹, J. Beardsley¹, A. G. Swartz², D. V. Pelekhov¹, M. E. Flatté³, R. K. Kawakami^1,2, J. Pelz¹, P. C. Hammel¹, and E. Johnston-Halperin^1,†

¹Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
²Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
³Departent of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA