Dependence of Electron Temperature on the Incident Microwave Power in the Photo-Excited GaAs/AlGaAs 2D Electron System
ORAL
Abstract
We examined the influence of microwave radiation on both amplitude of Shubnikov-de Haas (SdH) oscillations and null magnetic field longitudinal magnetoresistance at low temperatures, T<4.2 K, in GaAs/AlGaAs Hall bar devices. SdH oscillations have been analyzed over the parameter space given by 2.3<ωc/ω<5.2, where ωc=eB/m*, ω=2πf, B is the magnetic field, m* is the effective mass and f is the microwave frequency. Microwave radiation over the frequency range 30≤f≤100 GHz with peak source power 1≤P≤10 mW served to photo-excite a high mobility (107cm2/Vs). 2D electron system (2DES) as magnetoresistance traces were obtained as a function of the microwave power P and T. Then, fits of the SdH oscillations line shape served to extract the electron temperature (Te) as a function of P and T over the above-mentioned parameter window. Theory has proposed that, in the ωc/ω≥1 regime, both the electron temperature and radiation energy absorption rate (Sp) exhibit relatively constant response, while in ωc/ω≤1 regime, both Te and Sp exhibit oscillatory behavior. We compare the results of this experimental study with the theoretical predictions and correlate the Te and P.
*U.S. Department of Energy, DE-SC0001762. Army Research Office, W911NF-14-2-0076, and W911NF-15-1-0433
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Presenters
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Tharanga Nanayakkara
- Physics & Astronomy , Georgia State University
- Physics & Astronomy, Georgia State University
- Georgia State Univ
- Physics and Astronomy , Georgia State University
- Department of Physics, Georgia State University