[19p-W241-2~12] 10.4 半導体・有機・光・量子スピントロニクス

▲ [19p-W241-4] Helicity dependent photocurrent at RT from a Fe/x-AlO_x/p-GaAs Schottky junction

〇(D)Roca Ronel Intal¹、Nishizawa Nozomi¹、Munekata Hiro¹ (1.Tokyo Tech)

キーワード：spin dependent optical phenomena,spin photocurrent,spin photodiode

We report the observation of helicity dependent spin photocurrent at room temperature in a lateral spin photodiode based on a Schottky Fe/x-AlO_x/p-GaAs semiconductor structure. The circularly polarized light from a 785nm laser was shone onto the cleaved sidewall of the device. The spin photocurrent results show a saturation behaviour that is similar to the in-plane SQUID data of the Fe contact for |H| > 1kOe. While for H = 0, no spin photocurrent was detected, suggesting degradation in the magnetic quality or possibly the formation of magnetic domains at the Fe near the cleaved edge. From the normalized spin photocurrent value of 0.144%, we were also able to estimate the ratio of surviving spin polarization at the tunnnel barrier of ~0.32% by employing a model based on the ideal diode and Julliere tunneling.