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This study examines the magnetotransport response observed in flakes of the 3D topological insulator (TI) Bi2Te3, including indium superconducting electrodes, and demonstrates two critical transitions in the magnetoresistive response with decreasing temperatures below T = 3.4 K. The first transition is attributed to superconductivity in the indium electrodes, and the second transition, with a critical field exceeding the transition field of indium, is attributed to a proximity effect at the 2D planar interface of this hybrid TI/superconductor structure. [ABSTRACT FROM AUTHOR]

This study examines the magnetotransport response observed in flakes of the 3D topological insulator (TI) Bi2Te3, including indium superconducting electrodes, and demonstrates two critical transitions in the magnetoresistive response with decreasing temperatures below T = 3.4 K. The first transition is attributed to superconductivity in the indium electrodes, and the second transition, with a critical field exceeding the transition field of indium, is attributed to a proximity effect at the 2D planar interface of this hybrid TI/superconductor structure. [ABSTRACT FROM AUTHOR]

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 polarized microwave radiation induced magnetoresistance oscillations observed at low magnetic fields are similar to the oscillations observed with linearly polarized radiation. For the linearly polarized radiation, the magnetoresistive response is a strong sinusoidal function of the launcher rotation (or linear polarization) angle, θ. For circularly polarized radiation, the oscillatory magnetoresistive response is hardly sensitive to θ. [ABSTRACT FROM AUTHOR]

We examine the role of the microwave power in the linear polarization angle dependence of the microwave radiation induced magnetoresistance oscillations observed in the high mobility GaAs/AlGaAs two dimensional electron system. The diagonal resistance Rxx was measured at the fixed magnetic fields of the photo-excited oscillatory extrema of Rxx as a function of both the microwave power, P, and the linear polarization angle, h. Color contour plots of such measurements demonstrate the evolution of the lineshape of Rxx versus h with increasing microwave power. We report that the non-linear power dependence of the amplitude of the radiationinduced magnetoresistance oscillations distorts the cosine-square relation between Rxx and h at high power. [ABSTRACT FROM AUTHOR]

We report the results of a combined microwave polarization-dependence and power-dependence study of the microwave-radiation-induced magnetoresistance oscillations in high mobility GaAs/AlGaAs heterostructure devices at liquid helium temperatures. The diagonal resistance was measured with the magnetic field fixed at the extrema of the radiation-induced magnetoresistance oscillations, as the microwave power was varied at a number of microwave polarization angles. The results indicate a nonlinear relation between the oscillatory peak or valley magnetoresistance and the microwave power, as well as a cosine square relation between the oscillatory peak or valley magnetoresistance and the microwave polarization angle. The main features are briefly compared with the predictions of existing models. [ABSTRACT FROM AUTHOR]

We examine and compare the diagonal magnetoresistance, Rxx, and the photovoltage induced by microwave (42 ⩽ ƒ <300 GHz) and terahertz (ƒ ⩾ 300 GHz) photoexcitation in the high mobility quasi-two-dimensional GaAsIAIGaAs system. The data demonstrate strong radiation-induced magnetoresistance oscillations in Rxx to 360 GHz. In addition, cyclotron resonance is observed in the photovoltage to 725 GHz. These results show that our high-mobility GaAs/AIGaAs two-dimensional electron system (2DES) specimens remain photoactive in magnetotransport into the terahertz band. [ABSTRACT FROM AUTHOR]