Quantum Transport and Microwave Response inModulated High-Mobility Two-Dimensional ElectronSystems

[摘要] Two-dimensional electron gas (2DEG) in microwave irradiation has been an intriguingsystem to study transport properties of electrons for a decade, during whichextensive important phenomena have been discovered, such as microwave induced resistanceoscillation (MIRO), zero resistance state(ZRS) and zero conductance state(ZCS).Along this direction, this thesis is devoted to new phenomena recently discovered insuch systems, 1) microwave induced cyclotron harmonic peak (2wc spike) in ultraclean2DEG without antidots inducing electric modulation potential 2) Aharonov-Bohm(AB) oscillations in microwave irradiated 2DEG with modulation potential.Those phenomena originate from quantum interference, from either interplay betweentwo different kinds of scattering or different electrons transition paths.In addition to microwave induced phenomena, other nonlinear effects such as Zenertunneling and geometric resonance(GR) have been investigated further in the past fewyears and collected in this thesis. Zener tunneling has been found in two-dimensionalhole gas(2DHG) with a large damping factor, which inspires more questions on theunique band structures of holes. GR has been studied in ultra-clean modulated 2DEG, in which more oscillation peaks show up. In the GR regime with an inplane magneticfield applied, the antisymmetric hall oscillations lead us to propose the existence of amagnetic lattice along with an artificial antidots lattice and a current lattice in suchsystems.

[发布机构] Rice University

[效力级别] Astronomy