Department of Physics
Research, teaching and outreach in Physics at UW–Madison

Events

Events at Physics
<< Summer 2008 Fall 2008 Spring 2009 >>
Subscribe your calendar or receive email announcements of events
R. G. Herb Condensed Matter Seminar
Magnetotransport in Microwave-irradiated Quantum Hall Systems
Date: Thursday, October 9th
Time: 10:00 am
Place: Chamberlin 5310
Speaker: Michael Zudov, University of Minnesota
Abstract: When a high quality two-dimensional electron system is irradiated by microwaves, its magnetoresistance exhibits microwave-induced resistance oscillations (MIRO) and zero-resistance states. MIRO were discussed in terms of the aEurooedisplacementaEuro model, which is based on microwave-assisted impurity scattering, and the aEurooeinelasticaEuro model, stepping from the oscillatory electron distribution function. It is believed that the aEurooeinelasticaEuro contribution greatly exceeds the aEurooedisplacementaEuro contribution and can also account for MIRO temperature dependence.

This talk will discuss our recent experiments focusing on non-linear response and temperature dependence of MIRO. First, we show that the aEuro~aEuroTMdisplacementaEuroTMaEuroTM mechanism cannot be ignored and might even dominate the response under typical experimental conditions. Further, we find that the MIRO temperature dependence originates primarily from the temperature-dependent quantum lifetime entering the Dingle factor. We suggest that the main source of the modification of the quantum scattering rate is the contribution from electron-electron scattering, a quantity hardly available from other experiments.
Host: Vavilov
Add this event to your calendar