Muraki, K. and Lok, J. G. S. and Kraus, Stefan and Dietsche, W. and Klitzing, Klaus von and Schuh, Dieter and Bichler, Max and Wegscheider, Werner
Coulomb Drag as a Probe of the Nature of Compressible States in a Magnetic Field.
Physical Review Letters 92 (24), p. 246801.
Magnetodrag reveals the nature of compressible states and the underlying interplay of disorder and interactions. At ν=3/2 clear T4/3 dependence is observed, which signifies the metallic nature of the N=0 Landau level. In contrast, drag in higher Landau levels reveals an additional contribution, which anomalously grows with decreasing T before turning to zero following a thermal activation law. The anomalous drag is discussed in terms of electron-hole asymmetry arising from disorder and localization, and the crossover to normal drag at high fields as due to screening of disorder.