1. Femtosecond photocurrents at the FeRh/Pt interface
- Author
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Rostislav Mikhaylovskiy, Alexey Kimel, Rajasekhar Medapalli, Th. Rasing, Sheena Patel, G. Li, and Eric E. Fullerton
- Subjects
010302 applied physics ,Photocurrent ,Spin pumping ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,7. Clean energy ,Electromagnetic radiation ,law.invention ,Magnetization ,law ,Spectroscopy of Solids and Interfaces ,0103 physical sciences ,Femtosecond ,0210 nano-technology ,Ultrashort pulse ,Circular polarization - Abstract
Femtosecond laser excitations of FeRh/Pt bilayers launch an ultrafast pulse of electric photocurrents in the Pt-layer and subsequently result in the emission of electromagnetic radiation in the THz spectral range. Analysis of the THz emission as a function of the polarization of the femtosecond laser pulse, external magnetic field, sample temperature, and sample orientation shows that the photocurrent can emerge due to vertical spin pumping and photo-induced inverse spin-orbit torque at the FeRh/Pt interface. The vertical spin pumping from FeRh into Pt does not depend on the polarization of light and originates from ultrafast laser-induced demagnetization of the ferromagnetic phase of FeRh. The photo-induced inverse spin-orbit torque at the FeRh/Pt interface can be described in terms of a helicity-dependent effect of circularly polarized light on the magnetization of the ferromagnetic FeRh and the subsequent generation of a photocurrent. © 2020 Author(s).
- Published
- 2020