Optical detection of the breakdown phenomena of integer and fractional quantum Hall effects in GaAs/AlGaAs heterostructures

We have studied photoluminescence (PL) signals from GaAs/AlGaAs heterostructure devices in strong magnetic fields with finite current flowing in the Hall-bar samples. An additional PL peak was found when the current density exceeds the critical value of current-induced breakdown of the quantum Hall effect. This phenomenon gives us the information of heating property of electrons.