Transverse focusing of spin-polarized photocurrents

We measure transverse magnetically focused photocurrent signals in an InSb/InAlSb quantum well device. Using optical spin orientation by modulated circularly polarized light an electron spin-dependent signal is observed due to the spin-orbit interaction. Simulations of the focusing signal are performed using a classical billiard ball model, which includes both spin precession and a spin-dependent electron energy. The simulated data suggest that a signal dependent on the helicity of the incident light is expected for a Rashba parameter alpha > 0.1 eV angstrom and that a splitting of the focusing signal is not expected to be observed in linear polarized photocurrent and purely electrical measurements.