Evidence of radiation-driven Landau states in 2D electron systems: Magnetoresistance oscillations phase shift
Escuela Politécnica Superior, Universidad Carlos III - Leganes, Madrid, Spain and Unidad Asociada al Instituto de Ciencia de Materiales, CSIC - Cantoblanco, Madrid, 28049, Spain
Received: 25 January 2016
Accepted: 9 March 2016
We provide the ultimate explanation of one of the core features of microwave-induced magnetoresistance oscillations in high-mobility two-dimensional electron systems: the 1/4-cycle phase shift of minima. We start with the radiation-driven electron orbits model with the novel concept of scattering flight-time between Landau states. We calculate the extrema and nodes positions obtaining an exact coincidence with the experimental ones. The main finding is that the physical origin of the phase shift is a delay of of the radiation-driven Landau guiding center with respect to radiation, demonstrating the oscillating nature of the irradiated Landau states. We analyze the dependence of this minima on radiation frequency and power and its possible shift with the quality of the sample.
PACS: 73.40.-c – Electronic transport in interface structures / 73.50.-h – Electronic transport phenomena in thin films
© EPLA, 2016