arXiv subjects

Q. A. Ebner

Publications and source records attributed to Q. A. Ebner.

3 recordsLinked to original sources

arXiv2017

Microwave-induced resistance oscillations in a back-gated GaAs quantum well

We performed effective mass measurements employing microwave-induced resistance oscillation in a tunable-density GaAs/AlGaAs quantum well. Our main result is a clear observation of an effective mass increase with decreasing density, in general agreement with earlier studies which investigated the density dependence of the effective mass employing Shubnikov- de Haas oscillations. This finding provides further evidence that microwave-induced resistance oscillations are sensitive to electron-electron interactions and offer a convenient and accurate way to obtain the effective mass.

cond-mat.mes-hall↗

arXiv2014

Observation of microwave-induced resistance oscillations in strained Ge/SiGe quantum wells

Microwave-induced resistance oscillations (MIRO) have been extensively studied for more than a decade but, until now, have remained unique to GaAs/AlGaAs-based 2D electron systems. Here, we report on the first observation of MIRO in a 2D hole gas hosted in Ge/SiGe quantum well. Our findings confirm that MIRO is a universal phenomenon and demonstrate that microwave photoresistance can be utilized to probe the energy spectrum and the correlation effects of 2D holes in Ge/SiGe quantum wells.

cond-mat.mes-hall↗

arXiv2014

Colossal negative magnetoresistance in a 2D electron gas

We report on a colossal negative magnetoresistance (MR) in GaAs/AlGaAs quantum well which, at low temperatures, is manifested by a drop of the resistivity by more than an order of magnitude at a magnetic field $B \approx 1$ kG. In contrast to MR effects discussed earlier, the MR reported here is not parabolic, even at small $B$, and persists to much higher in-plane magnetic fields and temperatures. Remarkably, the temperature dependence of the resistivity at $B \approx 1$ kG is linear over the entire temperature range studied (from 1 to 30 K) and appears to coincide with the high-temperature limit of the zero-field resistivity, hinting on the important role of acoustic phonons.

cond-mat.mes-hall↗