Helicity dependent photocurrent in metal/semimetal bilayers
We have studied helicity dependent photocurrent (HDP) in metal/semimetal (Bi) bilayers. Compared to Bi single layer films, we find the HDP is enhanced in metal/Bi bilayers. For the bilayers, the sign of HDP under back illumination reverses from that of front illumination. Using spin transport calculations, we show that the HDP sign reversal under back illumination is caused by spin absorption and spin to charge conversion at the metal/Bi interface. These results show that the HDP can be used to assess interface states with strong spin orbit coupling.
Interface-enhanced helicity dependent photocurrent in metal/semimetal bilayers
H. Hirose, M. Kawaguchi, Y.-C. Lau, Z. Chi, F. Freimuth, K. Takanashi, M. Hayashi
Phys. Rev. B 103, 174437 (2021).
Spin orbit induced photocurrent found in Bi/Cu bilayer
Irradiation of circularly polarized light in the visible range generates a helicity dependent photocurrent in Cu/Bi bilayers. Such helicity photocurrent emerges perpendicular to the light incident plane. The effect may be caused by spin momentum locked bands at the Cu/Bi interface.
Circular photogalvanic effect in Cu/Bi bilayers
H. Hirose, N. Ito, M. Kawaguchi, Y. C. Lau, M. Hayashi
Appl. Phys. Lett. 113, 222404 (2018).