Abstract:
In high-quality ZnO/Mg$_x$Zn$_{1-x}$O heterojunctions, microwave-induced magnetoresistance oscillations have been investigated using a contactless technique. The basic detection principle relies on the measurements of a signal transmission in the radio frequency range ($f\sim 50$ MHz) between two T-shaped antennas, capacitively coupled to a two-dimensional electron system. When the sample is exposed to exciting microwave radiation with the frequency $F = 60$–$140$ GHz in low magnetic fields, at least three oscillations are well resolved in the high-frequency conductivity. The amplitude of the first oscillation is comparable in amplitude to Shubnikov–de Haas oscillations in strong magnetic fields. A significant advantage of this method is the absence of Ohmic contacts or metallization deposited on the sample surface, which provides additional information for understanding the origin of this phenomenon.
Citation:
A. R. Khisameeva, A. V. Shchepetilnikov, Yu. A. Nefyodov, I. V. Kukushkin, “Contactless observation of microwave induced resistance oscillations in ZnO/Mg$_x$Zn$_{1-x}$O heterojunction”, Pis'ma v Zh. Èksper. Teoret. Fiz., 114:5 (2021), 328–332; JETP Letters, 114:5 (2021), 279–283