BREAKDOWN OF THE DISSIPATIONLESS QUANTUM HALL STATE: QUANTISED STEPS AND ANALOGIES WITH CLASSICAL AND QUANTUM FLUID DYNAMICS |
| L. Eaves School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK |
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| The breakdown of the integer quantum Hall effect at high currents sometimes occurs as a series of regular steps in the dissipative voltage drop measured along the Hall bar. The steps were first seen clearly in two Hall bars used to maintain the US Resistance Standard, but have also been reported in other devices. It is proposed that the origin of the steps can be understood in terms of an instability in the dissipationless flow at high electron drift velocities. The instability is induced by impurity- or defect-related inter-Landau level scattering processes in local microscopic regions of the Hall bar. Electron--hole pairs (magneto-excitons) are generated in the quantum Hall fluid in these regions and that the electronic motion can be envisaged as a quantum analogue of the von Karman vortex street which forms when a classical fluid flows past an obstacle. |
| DOI: 10.12693/APhysPolA.100.205 PACS numbers: 73.43.Jn, 73.43.Cd, 73.61.Ey |