Terahertz-induced magnetoresistance oscillations in high-mobility 2D electron systems under bichromatic and multichromatic excitation

In this work, we investigated the magnetotransport under terahertz radiation in high-mobility two-dimensional electron systems, focusing on irradiation by bichromatic and multichromatic terahertz sources. We observed strong modulation of the Shubnikov-de Haas oscillations at sufficient terahertz radiation power. We determined that the origin of the modulation was the interference between the average distance advanced by the scattered electrons between irradiated Landau states and the available initial density of states at a certain magnetic field. In the case of multifrequency illumination, we found that with the appropriate frequencies, the irradiated magnetoresistance could reach an almost zero-resistance state regime even at moderate radiation power.This work is supported by the MINECO (Spain) under grat MAT2014-58241-P and ITN Grant 234970 (EU)