Circularly polarized light detector based on ferromagnet/semiconductor junctions

Abstract

Helicity-dependent photocurrent I has been detected successfully under experimental configuration that a circularly polarized light beam is impinged with a right angle on a cleaved sidewall of the Fe/x-AlOx/GaAs-based n-i-p double-heterostructure. The photocurrent I has showed a well-defined hysteresis loop which resembles that of the magnetization of the in-plane magnetized Fe layer in the devices. The value of I has been I 0.2 nA at 5 K under the remnant magnetization state. Study on temperature dependence of the relative I value at H = 0 has revealed that it is maximized at temperatures 125  150 K, and is still measurable at room temperature.