COLLAPSE OF QUANTIZED HALL RESISTANCE AND BREAKDOWN OF IQHE IN GAAS ALGAAS HETEROSTRUCTURES/

Collapse of quantized Hall resistance (QHR), not resulting from breakd own of the dissipa tionless current flow, is reported in the integer q uantum Hall effect (IQHE) state with i = 4 of GaAs/Al-0.3 Ga0.7As butt erfly-type Hall bars at high Hall electric fields. The Hall electric f ield F-H at the collapse of QHR is about 20% lower than the F-H for th e breakdown of the dissipationless current flow. The nature of differe nce between the effect of the F-H On the collapse of QHR and the effec t of the F-H On the breakdown is discussed.