Quantum transport properties of quantum Hall wires in the presence of correlated disorder

Kawarabayashi, Tohru; Ohtsuki, Tomi; Kettemann, Stefan; Struck, Alexander; Krämer, B.

doi:10.1016/j.physe.2007.08.005

Cited by 2 publications

(2 citation statements)

References 11 publications

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“…The fluctuation of the effective field is equivalent to the fluctuation of ω eff , which is independent of the energy. The fluctuation of E c is therefore larger for larger n. It is to be noted that this plateau width dependence on the sample has not been observed for the case of the correlated potential 22 . Now we discuss what determines the effective field of the sample which governs the conductance plateau transitions of a long wire in correlated disordered magnetic fields.…”

Section: Conductance Of Individual Samplesmentioning

confidence: 78%

“…For understanding the physics behind this shift, we have argued that the correlated potential can act as a potential barrier across the wire, which produces the same amount of shift for each plateau transition. It has also been found 22 by calculating the conductance for various values of energies keeping the disorder potential fixed, that though the size of the shifts depends considerably on the sample, the distance between successive transitions, namely the plateau width, is insensitive to the sample and is essentially the same as the bulk Landau level separation. The quantum Hall wire is therefore an interesting system where the potential correlation affects qualitatively its transport property.…”

Section: Introductionmentioning

confidence: 99%

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Conductance-plateau transitions in quantum Hall wires with spatially correlated random magnetic fields

et al. 2008

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Quantum transport properties in quantum Hall wires in the presence of spatially correlated disordered magnetic fields are investigated numerically. It is found that the correlation drastically changes the transport properties associated with the edge state, in contrast to the naive expectation that the correlation simply reduces the effect of disorder. In the presence of correlation, the separation between the successive conductance plateau transitions becomes larger than the bulk Landau level separation determined by the mean value of the disordered magnetic fields. The transition energies coincide with the Landau levels in an effective magnetic field stronger than the mean value of the disordered magnetic field. For a long wire, the strength of this effective magnetic field is of the order of the maximum value of the magnetic fields in the system. It is shown that the effective field is determined by a part where the stronger magnetic field region connects both edges of the wire.

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Section: Conductance Of Individual Samplesmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Conductance-plateau transitions in quantum Hall wires with spatially correlated random magnetic fields

et al. 2008

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The quantum Hall effect in narrow quantum wires

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Kawarabayashi

Zhuravlev

et al. 2008

Physica Status Solidi (b)

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The quantum phase diagram of disordered quantum wires in a strong magnetic field is reviewed. For uncorrelated disorder potential the 2‐terminal conductance, as calculated with the numerical transfer matrix method, shows zero temperature discontinuous transitions between exactly integer plateau values and zero. This is explained by the dimensional crossover of the bulk localisation length, which drives a transition from delocalised to localised edge states. In the thermodynamic limit, fixing the aspect ratio of the wire, there is a transition from the one dimensional chiral metal of extended edge states to localisation along the wire. In the vicinity of this chiral metal insulator transition (CMIT), states are identified which are superpositions of edge states with opposite chirality. The bulk contribution of such states is found to decrease with increasing wire width. Based on exact diagonalisation results for the eigenstates and their participation ratios, we conclude that these states are characteristic for the CMIT, and have the appearance of nonchiral edges states. Thereby these states are distinguishable from other states in the quantum Hall wire, namely, extended edge states, two‐dimensionally (2D) localized, quasi‐1D localized, and 2D critical states. In the presence of spatially correlated random potential we find with the numerical transfermatrix method that the potential correlation results in a shift of quantized conductance plateaus in long wires proportional to the strength of the random potential. This shift is found to be insensitive to the strength of magnetic fields and the same for all plateaus. A semiclassical explanation of this effect is proposed. We conclude with an outlook on modfications of the quantum phase diagram due to the spin degree of freedom of the electrons and their interactions. We discuss the stability of the phase diagram at finite temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Quantum transport properties of quantum Hall wires in the presence of correlated disorder

Cited by 2 publications

References 11 publications

Conductance-plateau transitions in quantum Hall wires with spatially correlated random magnetic fields

Conductance-plateau transitions in quantum Hall wires with spatially correlated random magnetic fields

The quantum Hall effect in narrow quantum wires

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