Shubnikov-de Haas oscillations in sub-terahertz regime

We carry out sub-terahertz magneto-transmission experiments in GaAs quantum wells. In addition to cyclotron resonance, several types of quantum oscillations can be observed: (i) AC Shubnikov-de Haas (SdH) oscillations in dynamic conductivity and (ii) MIRO-like quantum oscillations in transmission in low magnetic fields and high temperatures. The static quantum properties, SdH in DC resistance and MIRO (microwave-induced resistance oscillations), are measured in the same conditions. SdH at high frequencies deviate substantially from similar experiments in the static regime. The most important new effect is the phase beating at a rate equal to an integer times the cyclotron resonance (CR) frequency.