title: Resistance oscillations in two-dimensional electron systems induced by both ac and dc fields.
abstract: We report on magnetotransport measurements in a high-mobility two-dimensional electron system subject simultaneously to ac (microwave) and dc (Hall) fields. We find that dc excitation affects microwave photoresistance in a nontrivial way. Photoresistance maxima (minima) evolve into minima (maxima) and back, reflecting strong coupling and interplay of ac- and dc-induced effects. Most of our observations can be explained in terms of indirect electron transitions using a new, combined resonant condition. Observed quenching of microwave-induced zero resistance by a dc field cannot be unambiguously linked to a domain model, at least before a systematic theory treating both excitation types within a single framework is developed.
authors.affiliation: School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: M A
authors.initials: MA
authors.lastname: Zudov
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West