d'Ambrumenil, Nicholas

Tueday June 21, 2011
Time: 11:00
Place: HPF G 6
Host: Rudolf Morf, PSI

Model for the Dissipative Conductance in Fractional Quantum Hall States

Nicholas d'Ambrumenil
University of Warwick, Coventry, UK

I will discuss a model of dissipative transport in the fractional quantum Hall regime. The model takes account of tunneling through saddle points in the effective potential for excitations created by impurities. It predicts the temperature range over which activated behavior is observed and explains why this range nearly always corresponds to around a factor two in temperature in both integer quantum Hall and fractional quantum Hall systems. The ratio of the gap observed in the activated behavior and the temperature of the inflection point in the Arrhenius plot are shown to be an important diagnostic for determining the importance of tunneling in real samples.