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arxiv: 2410.07943 · v3 · pith:5ONYVMRTnew · submitted 2024-10-10 · ❄️ cond-mat.mes-hall

Current density distribution for the quantum Hall effect

Pith reviewed 2026-05-23 19:19 UTC · model grok-4.3

classification ❄️ cond-mat.mes-hall
keywords quantum Hall effectcurrent density distributionHall barpersistent currentedge currentsscreening propertiesinteger quantum Hall regime
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0 comments X

The pith

Accounting for voltage-dependent persistent currents, the imposed current in a quantum Hall bar flows unidirectionally only on the higher-potential edge while persistent currents run oppositely along the two edges.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes a revised picture of current flow in the integer quantum Hall regime by including a closed-loop persistent current whose density falls as Hall voltage rises. A sympathetic reader would care because this directly addresses the long-standing question of where the current actually travels when Hall resistance is quantized. The analysis rests on the screening behavior of the two-dimensional electron system, which allows the persistent current to form a loop inside the Hall bar. Once the voltage dependence is taken into account, the total current on one edge opposes the total current on the opposite edge, while the externally imposed current remains unidirectional and confined to the side connected to the higher electrical potential.

Core claim

Accounting for the dependence of persistent current density on Hall voltage, the current flows in the opposite directions along opposite edges of the Hall bar, while the imposed current flows unidirectionally and only on the side of the Hall bar connected with its higher electrical potential edge.

What carries the argument

Closed-loop persistent current whose density decreases with increasing Hall voltage, permitted by the screening properties of the two-dimensional electron system in the quantum Hall regime.

If this is right

  • Persistent current density inside the Hall bar falls as Hall voltage is increased.
  • The imposed current component remains unidirectional and is present only on the higher-potential edge.
  • Net current on one edge runs opposite to net current on the opposite edge.
  • The distribution is a direct consequence of the voltage dependence of the persistent loop current.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Local potential or current imaging experiments could map the predicted reversal between the two edges without changing gate voltage or magnetic field.
  • The same voltage dependence may alter predictions for dissipation or noise when contacts are placed asymmetrically along the bar.
  • If the persistent-current decay law can be measured independently, the model supplies a parameter-free relation between edge current asymmetry and applied Hall voltage.

Load-bearing premise

The screening properties of the two-dimensional electron system in the quantum Hall regime permit a closed-loop persistent current whose density decreases with increasing Hall voltage.

What would settle it

Local probe measurement of current direction or density along both long edges of a Hall bar at fixed filling factor, showing whether the net flow on the two edges is in opposite directions once Hall voltage exceeds a threshold set by the persistent-current decay.

Figures

Figures reproduced from arXiv: 2410.07943 by Serkan Sirt, Stefan Ludwig.

Figure 1
Figure 1. Figure 1: Qualitative sketches of the predictions of the screening [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Extension of Fig [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Illustration of geometry in (b) of the ICS corresponding to [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
read the original abstract

Our microscopic understanding of the integer quantum Hall effect is still incomplete. For decades, there has been a controversial discussion about "where the current flows" if the Hall resistance is quantized. Here, we qualitatively analyze the current density distribution in a Hall bar based on the screening properties of a two-dimensional electron system in the quantum Hall regime. Beyond previous publications, we include a closed loop persistent current that exists inside a Hall bar if the Hall resistance is quantized. We find, that the persistent current density decreases with increasing Hall voltage. Accounting for this dependence, we find, that the current flows in the opposite directions along opposite edges of the Hall bar, while the imposed current flows unidirectionally and only on the side of the Hall bar connected with its higher electrical potential edge.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript qualitatively analyzes current density in a quantum Hall bar, positing a closed-loop persistent current whose density decreases with Hall voltage due to 2DES screening properties. It concludes that this dependence causes persistent currents to flow oppositely along opposite edges while the imposed current flows unidirectionally only along the higher-potential edge.

Significance. If the asserted voltage dependence of persistent current density is shown to follow from screening (e.g., via explicit Thomas-Fermi or strip calculations), the work could address long-standing questions on current paths in the QHE. The manuscript supplies no such derivation or boundary conditions, so the result remains an assertion rather than a demonstrated outcome.

major comments (2)
  1. [Abstract] Abstract (paragraph beginning 'Beyond previous publications'): the central claim requires that screening produces a closed-loop persistent current whose density falls with rising Hall voltage; no explicit functional relation, Thomas-Fermi screening calculation, or incompressible-strip model is supplied to derive or justify this dependence. This relation is load-bearing for the opposite-edge-flow conclusion.
  2. [Abstract] Abstract (final sentence): the directional cancellation between imposed and persistent currents on opposite edges follows only if the persistent density decreases with voltage; if the density is voltage-independent or increases, the claimed unidirectional imposed-current picture does not hold. No test or limiting case is presented to confirm the sign of the dependence.
minor comments (1)
  1. [Abstract] The abstract refers to 'previous publications' without citations; add specific references to prior screening or persistent-current models.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments. Our manuscript presents a qualitative analysis; we address the points below and will make partial revisions to improve clarity.

read point-by-point responses
  1. Referee: [Abstract] Abstract (paragraph beginning 'Beyond previous publications'): the central claim requires that screening produces a closed-loop persistent current whose density falls with rising Hall voltage; no explicit functional relation, Thomas-Fermi screening calculation, or incompressible-strip model is supplied to derive or justify this dependence. This relation is load-bearing for the opposite-edge-flow conclusion.

    Authors: We agree that the manuscript is qualitative and supplies no explicit Thomas-Fermi or strip calculation. The claimed voltage dependence is motivated by the known screening behavior of the 2DES in the QHE regime, in which stronger Hall fields are screened by charge redistribution that reduces the amplitude of closed-loop persistent currents. We will revise the abstract and add a short qualitative paragraph in the main text that spells out this screening argument and cites relevant incompressible-strip literature. revision: partial

  2. Referee: [Abstract] Abstract (final sentence): the directional cancellation between imposed and persistent currents on opposite edges follows only if the persistent density decreases with voltage; if the density is voltage-independent or increases, the claimed unidirectional imposed-current picture does not hold. No test or limiting case is presented to confirm the sign of the dependence.

    Authors: The sign follows from the same screening physics: at vanishing Hall voltage the persistent loops are unscreened and strongest, while increasing voltage strengthens the perpendicular field that the 2DES screens, thereby lowering loop density. We will add a brief limiting-case discussion (zero-voltage maximum) to the revised text to make the sign explicit. revision: partial

Circularity Check

0 steps flagged

No circularity detected; no load-bearing steps reducible to inputs

full rationale

The abstract asserts a finding that persistent current density decreases with Hall voltage due to screening properties of the 2DES in the QHE regime, leading to opposite edge flows for persistent vs. imposed current. However, the provided text supplies no equations, no explicit functional dependence, no Thomas-Fermi or strip calculations, and no self-citations or ansatzes that could be inspected for self-definition, fitted-input renaming, or imported uniqueness. Without any quoted derivation chain that reduces by construction to its own inputs, no circular step of the enumerated kinds can be exhibited. The derivation is therefore treated as self-contained for the purpose of this analysis.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

Abstract-only review; ledger populated from statements visible in the abstract. The screening model and the existence of a voltage-dependent persistent current are taken as given without derivation shown.

axioms (1)
  • domain assumption Screening properties of a 2D electron system in the quantum Hall regime permit a closed-loop persistent current.
    Invoked in the sentence 'based on the screening properties of a two-dimensional electron system in the quantum Hall regime'.
invented entities (1)
  • voltage-dependent closed-loop persistent current no independent evidence
    purpose: To produce opposite current directions on opposite edges once its density is allowed to decrease with Hall voltage.
    Introduced in the abstract as an addition 'beyond previous publications'; no independent evidence or falsifiable prediction outside the model is stated.

pith-pipeline@v0.9.0 · 5652 in / 1372 out tokens · 25324 ms · 2026-05-23T19:19:46.795701+00:00 · methodology

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Reference graph

Works this paper leans on

29 extracted references · 29 canonical work pages

  1. [1]

    (Bureau inter- national des poids et mesures, 2019)

    BIPM, Le Syst `eme international d’unit ´es / The International System of Units (‘The SI Brochure’) , ninth ed. (Bureau inter- national des poids et mesures, 2019)

  2. [2]

    Delahaye and B

    F. Delahaye and B. Jeckelmann, Revised technical guidelines for reliable dc measurements of the quantized Hall resistance, Metrologia 40, 217 (2003)

  3. [3]

    N. Ofek, A. Bid, M. Heiblum, A. Stern, V . Uman- sky, and D. Mahalu, Role of interactions in an elec- tronic fabry–perot interferometer operating in the quantum hall effect regime, Proceedings of the Na- tional Academy of Sciences 107, 5276 (2010), https://www.pnas.org/doi/pdf/10.1073/pnas.0912624107

  4. [4]

    R. R. Gerhardts, The effect of screening on current distribution and conductance quantisation in narrow quantum Hall systems, physica status solidi (b) 245, 378 (2008)

  5. [5]

    B ¨uttiker, Four-terminal phase-coherent conductance, Phys

    M. B ¨uttiker, Four-terminal phase-coherent conductance, Phys. Rev. Lett. 57, 1761 (1986)

  6. [6]

    B ¨uttiker, Absence of backscattering in the quantum Hall ef- fect in multiprobe conductors, Phys

    M. B ¨uttiker, Absence of backscattering in the quantum Hall ef- fect in multiprobe conductors, Phys. Rev. B 38, 9375 (1988)

  7. [7]

    P. F. Fontein, J. A. Kleinen, P. Hendriks, F. A. P. Blom, J. H. Wolter, H. G. M. Lochs, F. A. J. M. Driessen, L. J. Giling, and C. W. J. Beenakker, Spatial potential distribution in GaAs/AlxGa1−xAs heterostructures under quantum hall con- ditions studied with the linear electro-optic effect, Phys. Rev. B 43, 12090 (1991)

  8. [8]

    Yacoby, H

    A. Yacoby, H. Hess, T. Fulton, L. Pfeiffer, and K. West, Elec- trical imaging of the quantum hall state, Solid State Communi- cations 111, 1 (1999)

  9. [9]

    K. L. McCormick, M. T. Woodside, M. Huang, M. Wu, P. L. McEuen, C. Duruoz, and J. S. Harris, Scanned potential mi- croscopy of edge and bulk currents in the quantum Hall regime, Phys. Rev. B 59, 4654 (1999)

  10. [10]

    Weitz, E

    P. Weitz, E. Ahlswede, J. Weis, K. Klitzing, and K. Eberl, Hall- potential investigations under quantum Hall conditions using scanning force microscopy, Physica E: Low-dimensional Sys- tems and Nanostructures 6, 247 (2000)

  11. [11]

    Siddiki and R

    A. Siddiki and R. R. Gerhardts, Thomas-fermi-poisson the- ory of screening for laterally confined and unconfined two- dimensional electron systems in strong magnetic fields, Phys. Rev. B 68, 125315 (2003)

  12. [12]

    Siddiki and R

    A. Siddiki and R. R. Gerhardts, Incompressible strips in dissi- pative Hall bars as origin of quantized Hall plateaus, Phys. Rev. B 70, 195335 (2004)

  13. [13]

    S. Sirt, V . Y . Umansky, A. Siddiki, and S. Ludwig, Transition from edge- to bulk-currents in the quantum hall regime, Applied Physics Letters 126, 243101 (2025)

  14. [14]

    S. Sirt, M. Kamm, V . Y . Umansky, and S. Ludwig, Chiral nature of current flow in the regime of the quantized hall effect (2024), arXiv:2407.01277 [cond-mat.mes-hall]

  15. [15]

    D. B. Chklovskii, B. I. Shklovskii, and L. I. Glazman, Electro- statics of edge channels, Phys. Rev. B 46, 4026 (1992). 6

  16. [16]

    D. B. Chklovskii, K. A. Matveev, and B. I. Shklovskii, Bal- listic conductance of interacting electrons in the quantum Hall regime, Phys. Rev. B 47, 12605 (1993)

  17. [17]

    M. M. Fogler and B. I. Shklovskii, Resistance of a long wire in the quantum Hall regime, Phys. Rev. B 50, 1656 (1994)

  18. [18]

    Lier and R

    K. Lier and R. R. Gerhardts, Self-consistent calculations of edge channels in laterally confined two-dimensional electron systems, Phys. Rev. B 50, 7757 (1994)

  19. [19]

    G ¨uven and R

    K. G ¨uven and R. R. Gerhardts, Self-consistent local equilib- rium model for density profile and distribution of dissipative currents in a hall bar under strong magnetic fields, Phys. Rev. B 67, 115327 (2003)

  20. [20]

    von Klitzing, G

    K. von Klitzing, G. Dorda, and M. Pepper, New method for high-accuracy determination of the fine-structure constant based on quantized Hall resistance, Phys. Rev. Lett. 45, 494 (1980)

  21. [21]

    U. Klaß, W. Dietsche, K. von Klitzing, and K. Ploog, Imag- ing of the dissipation in quantum-hall-effect experiments, Zeitschrift f¨ur Physik B Condensed Matter 82, 351 (1991)

  22. [22]

    Komiyama, H

    S. Komiyama, H. Sakuma, K. Ikushima, and K. Hirakawa, Electron temperature of hot spots in quantum hall conductors, Phys. Rev. B 73, 045333 (2006)

  23. [23]

    Armagnat and X

    P. Armagnat and X. Waintal, Reconciling edge states with com- pressible stripes in a ballistic mesoscopic conductor, Journal of Physics: Materials 3, 02LT01 (2020)

  24. [24]

    Panos, R

    K. Panos, R. R. Gerhardts, J. Weis, and K. von Klitzing, Current distribution and hall potential landscape towards breakdown of the quantum hall effect: a scanning force microscopy investiga- tion, New Journal of Physics 16, 113071 (2014)

  25. [25]

    Siddiki and R

    A. Siddiki and R. R. Gerhardts, Range-dependent disorder ef- fects on the plateau-widths calculated within the screening the- ory of the iqhe, International Journal of Modern Physics B 21, 1362 (2007)

  26. [26]

    Siddiki, J

    A. Siddiki, J. Horas, D. Kupidura, W. Wegscheider, and S. Lud- wig, Asymmetric nonlinear response of the quantized hall ef- fect, New Journal of Physics 12, 113011 (2010)

  27. [27]

    R. B. Laughlin, Quantized hall conductivity in two dimensions, Phys. Rev. B 23, 5632 (1981)

  28. [28]

    B. I. Halperin, Quantized hall conductance, current-carrying edge states, and the existence of extended states in a two- dimensional disordered potential, Phys. Rev. B25, 2185 (1982)

  29. [29]

    R. R. Gerhardts, Self-consistent theory of screening and trans- port in narrow, translation-invariant Hall bars under the con- ditions of the integer quantum-Hall-effect, Recent Progress in Materials 02, 007 (2020)