The rectified non-linear response of a clean undoped semiconductor to an ac electric field includes a well known intrinsic contribution — the shift current. We show that when Kramers degeneracy is broken, a distinct second-order rectified response appears that is due to Bloch state anomalous velocities in a system with an oscillating Fermi surface. This effect, which we refer to as the resonant photovoltaic effect (RPE), produces a resonant galvanic current peak at the interband absorption threshold in doped semiconductors or semimetals with approximate particle-hole symmetry. We evaluate the RPE for a model of the surface states of a magnetized topological insulator.
About the speaker
Dr Pankaj Bhalla is a Research Fellow at the University of New South Wales, working with Dr Dimi Culcer. He is from the Beijing Computational Science Research Centre in China.