An unusual photo-galvanic effect is predicted on the topological insulator surface when its semi-metallic electronic spectrum is modified by an adjacent ferromagnet. The effect is correlated with light absorption in a wide frequency range (from a few to hundreds of meV) and produces a pronounced response that is not only resonant to the photon energy but also tunable by an external electrical bias. The exceptionally strong peak photocurrent of the order of μA/cm may be achieved at elevated temperatures with the illumination power of 1 W/cm2 in the THz range on Bi2Se3. These advantages could enable room-temperature detection of far-infrared radiation.
@article{arxiv.1208.2619,
title = {Tunable photo-galvanic effect on topological insulator surfaces via proximity interactions},
author = {Yuriy G. Semenov and Xiaodong Li and Ki Wook Kim},
journal= {arXiv preprint arXiv:1208.2619},
year = {2015}
}