IPM Calendar  School/Center

Weekly Seminar
Elasto-Dynamical Induced Spin and Charge Pumping in Bulk Heavy Metals
Dr. Farzad Mahfouzi

Date : Wednesday , November 23, 2022
           11:00 - 12:00    

Acoustic waves and strain pulses created by a piezoelectric substrate represent an attractive tool for the generation of spin current to induce magnetization dynamics in magnetic materials and heterostructures. Acoustically induced excitations have the advantage of requiring much lower power consumption compared to the excitation by a microwave magnetic field. Analogous to the spin-Hall effect (SHE), using ab-initio electronic structure calculations we reveal that in nonmagnetic materials, acoustic phonons can induce charge (spin) current flowing along (normal to) its propagation direction. Using the Floquet approach we demonstrate that in bulk Pt, (i) the longitudinal phonon indued charge pumping originates from the Berry curvature, while the transverse pumped spin current is an odd function of the electronic relaxation time and diverges in the clean limit, (ii) The longitudinal charge current is of nonrelativstic origin, while the transverse spin current is a relativistic effect that to lowest order scales linearly with the spin-orbit coupling strength, (iii) Both charge and spin pumped currents have parabolic dependence on the amplitude of the elastic wave as expected from the rectification effect.