Submillimeter wave induced resistance oscillations in ultra-high mobility two-dimensional electron systems

Submillimeter wave induced resistance oscillations in two ultra-high mobility GaAs/Al0.24Ga0.76As quantum well samples have been investigated by means of a backward wave oscillator and far-infrared laser at 3He temperatures. Subnikov–de Haas oscillation, submillimeter wave induced resistance oscillation, and magnetoplasmon resonance occur simultaneously in this frequency regime. The primary radiation induced resistance minimum shifts toward cyclotron resonance with increasing radiation frequency. The positions of these minima agree well with those of the magnetoplasmon resonance. The higher-order harmonics of the resistance oscillation remain around the multiples of the cyclotron resonance frequency. An in situ transmission measurement exhibits an asymmetric broadening of the cyclotron resonance, appearing as a combination of the cyclotron resonance and the magnetoplasmon resonance, but no features directly linked to the microwave induced resistance oscillation can be seen.