Spin-current injection and detection in κ -(BEDT-TTF)2Cu[N(CN)2]Br

Abstract

Spin-current injection into an organic semiconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br film induced by the spin pumping from an yttrium iron garnet (YIG) film. When magnetization dynamics in the YIG film is excited by ferromagnetic or spin-wave resonance, a voltage signal was found to appear in the κ-(BEDT-TTF)2Cu[N(CN)2]Br film. Magnetic-field-angle dependence measurements indicate that the voltage signal is governed by the inverse spin Hall effect in κ-(BEDT-TTF)2Cu[N(CN)2]Br. We found that the voltage signal in the κ-(BEDT-TTF)2Cu[N(CN)2]Br/YIG system is critically suppressed around 80 K, around which magnetic and/or glass transitions occur, implying that the efficiency of the spin-current injection is suppressed by fluctuations which critically enhanced near the transitions.