Bistability in the current-induced breakdown of the quantum Hall effect

The structure of the longitudinal resistance in the breakdown behaviour of the quantum Hall effect (QHE) of GaAs/AlGaAs heterostructures is studied at a temperature of about 100 mK using samples with a constricted current path. Time-resolved measurements on a sample with a 50 mu m wide constriction...

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Bibliographic Details
Published in:Semiconductor science and technology 1993-12, Vol.8 (12), p.2062-2068
Main Authors: Ahlers, F J, Hein, G, Scherer, H, Bilek, L, Nickel, H, Losch, R, Schlapp, W
Format: Article
Language:English
Subjects:
Condensed matter: electronic structure, electrical, magnetic, and optical properties
Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures
Electronic transport in interface structures
Exact sciences and technology
Physics
Quantum hall effect (including fractional)
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Summary:The structure of the longitudinal resistance in the breakdown behaviour of the quantum Hall effect (QHE) of GaAs/AlGaAs heterostructures is studied at a temperature of about 100 mK using samples with a constricted current path. Time-resolved measurements on a sample with a 50 mu m wide constriction show that the current-induced breakdown of the QHE evolves as a switching between at least two states, a non-dissipative one and a resistive one. The two states may coexist in some region of magnetic field and sample current. This shows up in the time behaviour of the longitudinal voltage, which is time-distributed in a statistical manner. Increasing the sample current at fixed magnetic field increases the time the current carriers stay in the resistive state rho sub(dis) until at high enough currents all backswitching into the non-dissipative state is suppressed. At filling factors nu < 2, the resistivity rho sub(dis) increases linearly with the difference, Delta nu identical with nu - nu sub(i) with nu sub(i) identical with 2. The corresponding voltages are found to be less than h-bar omega sub(c)/e at all sample currents, contrary to results of Cage et al. For filling factors with nu greater than or equal to 2 the sample shows no similar effect. The results will be discussed within the framework of several existing models for the breakdown behaviour of the QHE.
ISSN:0268-1242
1361-6641
DOI:10.1088/0268-1242/8/12/005