Microwave response of interacting oxide two-dimensional electron systems
Abstract
We present an experimental study on microwave illuminated high mobility MgZnO/ZnO based two-dimensional electron systems with different electron densities and, hence, varying Coulomb interaction strength. The photoresponse of the low-temperature dc resistance in perpendicular magnetic field is examined in low and high density samples over a broad range of illumination frequencies. In low density samples a response due to cyclotron resonance (CR) absorption dominates, while high density samples exhibit pronounced microwave-induced resistance oscillations (MIRO). Microwave transmission experiments serve as a complementary means of detecting the CR over the entire range of electron densities and as a reference for the band mass unrenormalized by interactions. Both CR and MIRO-associated features in the resistance permit extraction of the effective mass of electrons but yield two distinct values. The conventional cyclotron mass representing center-of-mass dynamics exhibits no change with density and coincides with the band electron mass of bulk ZnO, while MIRO mass reveals a systematic increase with lowering electron density consistent with renormalization expected in interacting Fermi liquids.
Cite
@article{arxiv.2006.13627,
title = {Microwave response of interacting oxide two-dimensional electron systems},
author = {D. Tabrea and I. A. Dmitriev and S. I. Dorozhkin and B. P. Gorshunov and A. V. Boris and Y. Kozuka and A. Tsukazaki and M. Kawasaki and K. von Klitzing and J. Falson},
journal= {arXiv preprint arXiv:2006.13627},
year = {2020}
}