We use the nonequilibrium bosonization technique to investigate the effects of the Coulomb interaction on quantum Hall edge states at a filling factor $\nu =2$, partitioned by a quantum point contact (QPC). We find that, due to the integrability of charge dynamics, edge states evolve to a nonequilibrium stationary state with a number of specific features. In particular, the noise temperature $\Theta$ of a weak backscattering current between edge channels is linear in voltage bias applied at the QPC, independently of the interaction strength. In addition, it is a nonanalytical function of the QPC transparency $T$ and scales as $\Theta \propto T\ln (1/T)$ at $T\ll 1$. Our predictions are confirmed by exact numerical calculations.

• Received 25 June 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.246806