The emerging material, topological insulator, has provided new opportunities for spintronic applications, owing to its strong spin-orbit character. Topological insulator based heterostructures that display spin-charge coupling driven by topology at surfaces have great potential for the realization of novel spintronic devices. Here, we report the observation of anomalous photogalvanic effect in (Bi0.5Sb0.5)2Te3 thin films grown on GaAs substrate. We demonstrate that the magnitude, direction, and temperature dependence of the helicity-dependent photocurrent (HDPC) can be modulated by the gate voltage. From spatially resolved photocurrent measurements, we show that the line profile of HDPC in (Bi0.5Sb0.5)2Te3/GaAs is unaffected by the variation of beam size, in contrast to the photocurrent response measured in a (Bi0.5Sb0.5)2Te3/mica structure.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics