CURRENT SCALING IN THE INTEGER QUANTUM HALL-EFFECT

We report a current (I)-dependent transport measurement in between two adjacent integer quantum Hall plateaus at different bath temperatures (Tb) for 10 nA<I<10 μA. We find the maximum slope in ρxy scales with I when I is larger than a characteristic value. Combined with previous T scaling results, we find the current-dependent effective temperature of the two-dimensional electron gas in the integer quantum Hall effect regime, Te∼I0.5, independent of Landau levels and the spin degeneracy. This result allows us to deduce that p=2 for the T exponent of the inelastic scattering length (lin∼Te-p/2). Therefore, the values of the localization exponent ν and of the dynamical exponent z can be obtained directly and independently. © 1994 The American Physical Society.