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The observation of vanishing electrical resistance in condensed matter has led to the discovery of new phenomena such as, for example, superconductivity, where a zero-resistance state can be detected in a metal below a transition temperature T(c) (ref. 1). More recently, quantum Hall effects were discovered from investigations of zero-resistance states at(More)
Electronic carriers in graphene show a high carrier mobility at room temperature. Thus, this system is widely viewed as a potential future charge-based high-speed electronic material to complement-or replace-silicon. At the same time, the spin properties of graphene have suggested improved capability for spin-based electronics or spintronics and spin-based(More)
We examine the microwave-photoexcited magnetoresistance oscillations in a tilted magnetic field in the high-mobility two-dimensional electron system ͑2DES͒. In analogy to the 2D Shubnikov–de Haas effect, the characteristic field B f and the period of the radiation-induced magnetoresistance oscillations appear dependent upon the component of the applied(More)
Large changes in the electrical resistance induced by the application of a small magnetic field are potentially useful for device-applications. Such Giant Magneto-Resistance (GMR) effects also provide new insights into the physical phenomena involved in the associated electronic transport. This study examines a "bell-shape" negative GMR that grows in(More)
We examine and compare the diagonal magnetoresistance, R xx , and the photovoltage induced by microwave (42 f < 300 GHz) and terahertz (f 300 GHz) photoexcitation in the high mobility quasi-two-dimensional GaAs/AlGaAs system. The data demonstrate strong radiation-induced magnetoresistance oscillations in R xx to 360 GHz. In addition, cyclotron resonance is(More)
High mobility two-dimensional electron systems exhibit vanishing resistance over broad magnetic field intervals upon excitation with microwaves, with a characteristic reduction of the resistance with increasing radiation intensity at the resistance minima. Here, we report experimental results examining the voltage-current characteristics, and the resistance(More)
Negative diagonal magneto-conductivity/resistivity is a spectacular- and thought provoking-property of driven, far-from-equilibrium, low dimensional electronic systems. The physical response of this exotic electronic state is not yet fully understood since it is rarely encountered in experiment. The microwave-radiation-induced zero-resistance state in the(More)
A comparative study of the radiation-induced magnetoresistance oscillations in the high mobility GaAs/AlGaAs heterostructure two dimensional electron system (2DES) under linearly- and circularly- polarized microwave excitation indicates a profound difference in the response observed upon rotating the microwave launcher for the two cases, although circularly(More)
  • Aruna N. Ramanayaka, N. RAMANAYAKA, +4 authors Douglas Gies
  • 2015
This thesis consists of two parts. The first part considers the effect of microwave radiation on magnetotransport in high quality GaAs/AlGaAs heterostructure two dimensional electron systems. The effect of microwave (MW) radiation on electron temperature was studied by investigating the amplitude of the Shubnikov de Haas (SdH) oscillations in a regime where(More)