Energy relaxation enhancement in a quantized two-dimensional interacting carrier system in a magnetic field.

We study low-temperature energy relaxation between a system of low-density holes with a high interaction parameter r_s (>20) and the host GaAs/AlGaAs quantum well lattice. Compared to the B=0 case, we find a significant enhancement of the energy relaxation rate when the system is tuned to a dissipative state between adjacent Quantum Hall plateaus. We find qualitatively similar behavior in samples with 2DES grown on [311] and [001] crystallographic planes. We also find a lower-than-expected exponent in the temperature dependence of the power flow between 2DES and the host, compare the results to available predictions and discuss the 2DES density dependence of the observed effect.