Critical current density for the dissipationless quantum Hall effect

This paper reports on an experimental study of the contact resistance of Hall bars in the Quantum Hall Effect regime while increasing the current through the sample. These measurements involve also the longitudinal resistance and they have been always performed before the breakdown of the Quantum Hall Effect. Our investigations are restricted to the i = 2 plateau which is used in all metrological measurements of the von Klitzing constant R K . A particular care has been taken concerning the configuration of the measurement. Four configurations were used for each Hall bar by reversing the current and the magnetic field polarities. Several samples with different width have been studied and we observed that the critical current for the contact resistance increases with the width of the Hall bar as previously observed for the critical current of the longitudinal resistance. The critical currents exhibit either a linear or a sublinear increase. All our observations are interpreted in the current understanding of the Quantum hall effect brekdown. Our analysis suggests that a heated region appears at the current contact, develops and then extends in the whole sample while increasing the current. Consequently, we propose to use the contact resistance as an electronic thermometer for the Hall fluid.

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“…This dependence is generally understood in terms of Inter Landau levels transitions [29,34,35,36,37,38,39].…”

Section: Resultsmentioning

confidence: 99%

Behavior of the contacts of quantum Hall effect devices at high currents

Meziani¹,

Chaubet²,

Bonifacie³

et al. 2004

Journal of Applied Physics

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“…The lithographic width of the QPC is approximately 600 nm. The geometry of this constriction is similar to those used by Bliek et al 19 and Kawaguchi et al; 11 however, we have an added advantage of being able to change the width of the constriction by varying the voltage applied to the gates. The sample is cooled in a dilution refrigerator with a base electron temperature of ~13 mK.…”

Section: Methodsmentioning

confidence: 99%

Breakdown of the integer and fractional quantum Hall states in a quantum point contact

Dillard

Lin

Kastner

et al. 2013

Physica E: Low-dimensional Systems and Nanostructures

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Abstract:The integer and fractional quantum Hall states are known to break down at high dc bias, exhibiting deviation from the ideal incompressible behavior. We measure breakdown of the ν = 2, 3, 4, 5 integer and the ν = 4/3 and 5/3 fractional states in a quantum point contact (QPC) of lithographic width ~600 nm. Dependence of the critical current on magnetic field, QPC gate voltage, and QPC width are presented. Of particular interest, the critical current of the 4/3 and 5/3 fractional states shows the opposite dependence on QPC width compared to the integer states. This previously unobserved result is not explained by current theories of breakdown.

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“…For high precision measurements with relative uncertainties as low as 10 Ϫ9 , the sample current should be as high as possible but below the critical current where the nearly nondissipative current flow breaks down. Therefore, a lot of experiments on samples with different material properties 2-4 and geometries [5][6][7] have been performed to understand the physics of the breakdown of the QHE. Since these results are hardly reconcilable within one conclusive model, different mechanisms for the breakdown as intra-Landau-level 8 and inter-Landau-level transitions, 9 or a phenomenological description on the basis of electron heating, 10,11 are still under debate.…”

mentioning

confidence: 99%

Breakdown of the quantum Hall effect in periodic and aperiodic antidot arrays

et al. 1997

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We have studied the breakdown of the quantum Hall effect in GaAs/Al x Ga 1Ϫx As heterostructures with antidot arrays as a function of the density and distribution of antidots. For periodic arrays ͑lithographic antidot diameter 100 nm͒ and periods from 400 to 1000 nm, the breakdown current is systematically reduced with increasing antidot density and determined by the peak value of the local current density. In aperiodic arrays, the breakdown current is markedly lower than in periodic arrays of the same antidot density due to higher local current densities at the same total current.

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Critical current density for the dissipationless quantum Hall effect

Abstract: In quantum Hall effect experiments, there is a critical measuring current, beyond which dissipation becomes apparent. Using samples with a narrow constriction in the middle, we have observed critical current densities which are much higher than previously reported values.

Cited by 55 publications

References 8 publications

Behavior of the contacts of quantum Hall effect devices at high currents

Behavior of the contacts of quantum Hall effect devices at high currents

Breakdown of the integer and fractional quantum Hall states in a quantum point contact

Breakdown of the quantum Hall effect in periodic and aperiodic antidot arrays

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