Ratchet effect induced by linearly polarized near- and mid-infrared radiation in InAs nanowires patterned quasi two-dimensional electron system

In this letter, we studied the polarization dependent current excited by near- and mid-infrared radiations in InAs nanowires patterned quasi two-dimensional structures. We observed a current with a predominated direction along the wires at normal incidence of mid-infrared radiation and attributed it to the ratchet effect. Photogalvanic effect induced by obliquely incident excitation is also observed. Under near-infrared excitation, however, the normal incident ratchet effect becomes insignificant and the linear photogalvanic effect at oblique incidence dominantly contributes to the electric current.