Scaling of thermoelectric voltage induced by microwave radiation at the boundary between two-dimensional electron systems

Abstract

We report measurements of the rectification of microwave radiation ͑0.7-20 GHz͒ at the boundary between two-dimensional electron systems created by a narrow gap split gate on a silicon surface for different temperatures, electron densities, and microwave power. For frequencies above 4 GHz and different temperatures, the rectified voltage V dc as a function of microwave power P can be collapsed onto a single universal curve V dc * = f * ͑P * ͒ using two scaling parameters. The scaled voltage V dc * is a linear function of power P * for small power and proportional to ͑P * ͒ 1/2 at higher power. A theory is developed which attributes the observed voltage to the thermoelectric response associated with local heating by the microwave radiation of adjacent twodimensional electron systems with different densities n 1 and n 2 . Excellent quantitative agreement is obtained between theory and experiment.

Nonlinear Transport of 2d Electrons in Crossed Electric and Quantizing Magnetic Fields

“…The enhancement of the higher harmonic content is in apparent contradiction with the description of the dc biased electrons by an elevated temperature T e : high temperature reduces exponentially the higher harmonic content of the oscillations. 56,114,115 A similar strong suppression of the resistance has also been observed in a microwave photoresponse. 39 In several recent papers, 46,56,69,70 the strong decrease of the resistance with the dc bias has been attributed to a non-uniform spectral diffusion of 2D electrons through Landau levels.…”

“…56,114,115 A similar strong suppression of the resistance has also been observed in a microwave photoresponse. 39 In several recent papers, 46,56,69,70 the strong decrease of the resistance with the dc bias has been attributed to a non-uniform spectral diffusion of 2D electrons through Landau levels. 82,100,105 The spectral diffusion generates a non-equilibrium electron distribution, which is significantly different from the Fermi-Dirac form.…”

“…135 Despite the apparent applicability of the T e approximation to the overheated electron systems, recent studies have revealed an inadequacy of the temperature description of the nonlinear transport of highly mobile 2D carriers in quantizing magnetic fields. 46,56,69,70 Figure 3 demonstrates the significant difference between effects of the temperature and the dc bias on the magnetoresistance. The figure shows three dependencies of the longitudinal resistance on the magnetic field.…”

Crossover from Fermi Liquid to Multichannel Luttinger Liquid in High-Mobility Quantum Wires

“…In this Letter, we present new data on the temperature dependence of the conductance in long quasi-1D weakly disordered quantum wires. We investigate the transport in high-mobility wires of submicron width that are formed by the split-gate technique in a two-dimensional electron gas (2DEG) [13,14]. This technique allows us to vary the width of the relatively long wire while maintaining high electron mobility within it, ensuring that the condition T > 1 is fulfilled above 1 K. For wire widths ranging from 90 to 180 nm, we observe a clear logarithmic temperature dependence of the conductance in the range 1-10 K. The logarithmic term increases as the width of the wire decreases.…”