Multi-Photon Transitions in Coupled Plasmon-Cyclotron Resonance Measured   by Millimeter-Wave Reflection
  We construct a low-temperature microwave waveguide interferometer for measuring high-frequency properties of two-dimensional electron gases (2DEGs). Coupled plasmon-cyclotron resonance (PCR) spectra are used to extract effective mass, bulk plasmon frequency, and carrier relaxation times. In contrast to traditional transmission spectroscopy, this method does not require sample preparation and is nondestructive. PCR signals can be resolved with a microwave power source as low as 10 nW. We observe PCR in the multi-photon transition regime, which has been proposed to be relevant to the microwave-induced resistance oscillations. 
Jie Zhang, Ruiyuan Liu, Rui-Rui Du, L. N. Pfeiffer, K. W. West
cond-mat.mes-hall