Microwave-induced zero-resistance states in a high-mobility two-subband electron system

Abstract

In this study we used selectively-doped GaAs/AlAs heterostructure to fabricate a high-mobility two-subband electronic system with substantially different concentration of electrons in subbands. We observe microwave photoresistance at high numbers of magneto-intersubband oscillations (MISO). The system under study demonstrates microwave-induced resistance oscillations (MIRO) and MISO interference. MIRO in the studied two-subband system appear in lower magnetic fields comparing to MISO. This is an indication of some unknown mechanism that exists in the two-subband system and is responsible for MISO amplitude damping in low magnetic fields, while it does not affect the MIRO amplitude. Zero resistance states (ZRS) appear in the system under study under microwave irradiation in the narrow range of magnetic fields near the MISO maximum.

Suppression of Magneto-Intersubband Resistance Oscillations by Large-Scale Fluctuations of the Intersubband Energy Splitting

“…It was shown that they are described by linear dependences, and the quantities τ q1 and τ q2 , which are calculated from their slope, are significantly different. Dingle plots for MIS oscillations were studied only in GaAs quantum wells with AlAs/GaAs lateral superlattice barriers [19][20][21][22]. It was also established that the dependences on 1/ in such heterostructures at K are nonlinear.…”

Microwave-Induced Magneto-Intersubband Scattering in a Square Lattice of Antidots

“…To date, ω/ωc oscillations have been observed in both single-and two-band electron systems [14][15][16]. A distinct feature of the microwave photoresistance of a two-subband electron system, as compared to a singlesubband system, is interference between ω/ωc resistance oscillations and MISOs [15].…”