Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Applied Science and Convergence Technology

Electron Interference in a Quantum Ring with a Tunable Magnetic Field Shield

Minky Seo, Hwanchul Jung, Yunhcul Chung

Published Mar 31, 2021• 2 citations
Publisher

Abstract

A quantum ring device that can turn on and off the external magnetic field on the ring is developed.The device is to study the effect of the interaction between electrons and external magnetic fields on Aharonov-Bohm interference.The switching is realized by employing a superconducting shield gate and turning on and off the superconductivity on the gate with applied current or magnetic field.The electron interference due to Aharonov-Bohm effect is observed regardless of the presence of the external magnetic field on the electron path of the ring.The result is consistent with the fact that effects of potentials on charged particles exists even in the region where all the field vanish hence no direct interaction between electron and magnetic field is allowed.

DOI
10.5757/asct.2021.30.2.62

Related papers

Aharonov-Bohm effect: influence of the electron's field, and speculations on the possibility of shielding

Michael A. Peshkin

Aharonov-Bohm (AB) effect is discussed from a viewpoint which stresses the influence of the fields whose source is the scattered particle. Speculations are presented to suggest that AB scattering may be influenced by subtle properties of superconducting surfaces which may shield the particle's fields away from the external magnetic field. Experiments are required to test the reality of such speculations. If such shielding effects can be measured, AB effect may become a sensitive probe to search for unusual surface states which display off diagonal long range order.

•Jan 1, 1983•1 citation

Locality of the Aharonov-Bohm-Casher effect

Kicheon Kang

We address the question of locality versus nonlocality in the Aharonov-Bohm and the Aharonov-Casher effects. For this purpose, we investigate all possible configurations of ideal shielding of the overlap between the electromagnetic fields generated by a charge and by a magnetic flux and analyze their consequences on the Aharonov-Bohm-Casher interference. In a classical treatment of shielding, the Aharonov-Bohm-Casher effect vanishes regardless of the geometry of shielding when the local overlap of electromagnetic fields is completely eliminated. On the other hand, the result depends on the configuration of shielding if the charge quantization in the superconducting shield is taken into account. It is shown that our results are fully understood in terms of the fluctuating local-field interaction. Our analysis strongly supports the alternative view on the Aharonov-Bohm-Casher interference that the effects originate from the local action of electromagnetic fields.

arXiv:1408.0607•Physical Review A•May 22, 2015•20 citations

Utilising the Aharonov-Bohm effect in quantum device design

Keith J. Kasunic

The Aharonov-Bohm effect – where electron-interference fringe positions are shifted based on the presence of a non-local magnetic field – has not yet been utilised to its full potential in quantum device design. In this paper, we show that the de Broglie wavelength of the electron is changed locally by its interaction with the magnetic vector potential. The vector potential thus acts as a quantum “phase plate”, changing the phase difference between interfering electron wavefunctions in a non-dispersive, gauge-invariant manner. This model is then shown to be applicable to the design and optimisation of phase-dependent quantum devices such as superconducting quantum interference devices (SQUIDs), quantum sensors, and so on.

Quantum Nanophotonic Materials, Devices, and Systems•Sep 3, 2019•0 citations

Shielded, local Aharonov-Bohm effects: how quantum phases cannot be stopped

Pablo L. Saldanha, Chiara Marletto, Vlatko Vedral

Both classical and quantum wave interference phenomena rely on the notion of phase. In both classical as well as quantum electrodynamics the phases are acquired locally; however, the quantum phases have the additional property that they can be transmitted even when the classical value of the degree of freedom relevant for the transfer (such as the value of the electric field at one point) are zero. Here we use a covariant formalism that is capable of explaining the electric and magnetic versions of the Aharonov-Bohm effect, as well as the Aharonov-Casher effect, through local interactions of charges and currents with the quantum electromagnetic field. We show that Aharonov-Bohm effect, which is just another instance of interference based on a quantum phase, is present even if the solenoid generating the magnetic field is shielded by a superconductor. This is because even though the classical value of the magnetic field is zero in the superconductor (the Meissner effect), the quantum operators pertaining to the magnetic field are non-zero and are furthermore responsible for transmitting the phase information between the solenoid and the electron. The conclusion of our work is that quantum phases cannot be shielded and we believe that this, among other consequences, finally resolves the last outstanding mystery in the Aharonov-Bohm effect.

•Nov 17, 2020•2 citations

Aharonov-Bohm interference in the presence of metallic mesoscopic cylinders

Silviu Olariu

This work studies the interference of electrons in the presence of a line of magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low temperature. It is found that, while there is a supplementary phase contribution from each electron of the mesoscopic cylinder, the sum of these individual supplementary phases is equal to zero, so that the presence of a normal-conducting mesoscopic ring at low temperature does not change the Aharonov-Bohm interference pattern of the incident electron. It is shown that it is not possible to ascertain by experimental observation that the shielding electrons have responded to the field of an incident electron, and at the same time to preserve the interference pattern of the incident electron. It is also shown that the measuring of the transient magnetic field in the region between the two paths of an electron interference experiment with an accuracy at least equal to the magnetic field of the incident electron generates a phase uncertainty which destroys the interference pattern.

arXiv:quant-ph/9702024•Physical Review A•Jan 1, 1997•0 citations

The Aharonov–Bohm Effect: Gauge Potentials, Quantum Phase, and Experimental Evidence

Giancarmine Sparso

This technical note gives a self-contained exposition of the Aharonov–Bohm effect, aimed at advanced undergraduate students. Starting from the role of electromagnetic potentials in classical electrodynamics, it introduces gauge freedom, the quantum Hamiltonian with minimal coupling, and the gauge covariance of the Schrödinger equation. It then derives the Aharonov–Bohm phase for both the time-dependent scalar configuration and the magnetic configuration, showing how a charged particle acquires an observable phase shift while travelling only through regions where the electromagnetic field vanishes. The final part reviews the experimental evidence, from the early electron-interference experiments of Chambers and of Möllenstedt and Bayh to the 1986 toroidal-magnet experiment of Tonomura and collaborators. In that experiment, superconducting shielding confined the magnetic flux completely and closed the leakage-field loophole, while flux quantization produced the characteristic half-fringe shift. The note is expository and pedagogical: it does not present original research results and has not been peer reviewed. Originally developed from study notes prepared for the PHYS02 scientific talk at Lady Margaret Hall, Oxford, in July 2026; an earlier version of the notes has been publicly available on GitHub since August 2026. Corrections and comments are more than welcome at giancarminesparso@gmail.com.

•Jul 1, 2026•0 citations
A quantum ring device that can turn on and off the external magnetic field on the ring is developed.The device is to study the effect of the interaction between electrons and external magnetic fields on Aharonov-Bohm interference.The switching is realized by employing a superconducting shield gate and turning on and off the superconductivity on the gate with applied current or magnetic field.The electron interference due to Aharonov-Bohm effect is observed regardless of the presence of the external magnetic field on the electron path of the ring.The result is consistent with the fact that effects of potentials on charged particles exists even in the region where all the field vanish hence no direct interaction between electron and magnetic field is allowed.
Aharonov-Bohm (AB) effect is discussed from a viewpoint which stresses the influence of the fields whose source is the scattered particle. Speculations are presented to suggest that AB scattering may be influenced by subtle properties of superconducting surfaces which may shield the particle's fields away from the external magnetic field. Experiments are required to test the reality of such speculations. If such shielding effects can be measured, AB effect may become a sensitive probe to search for unusual surface states which display off diagonal long range order.
We address the question of locality versus nonlocality in the Aharonov-Bohm and the Aharonov-Casher effects. For this purpose, we investigate all possible configurations of ideal shielding of the overlap between the electromagnetic fields generated by a charge and by a magnetic flux and analyze their consequences on the Aharonov-Bohm-Casher interference. In a classical treatment of shielding, the Aharonov-Bohm-Casher effect vanishes regardless of the geometry of shielding when the local overlap of electromagnetic fields is completely eliminated. On the other hand, the result depends on the configuration of shielding if the charge quantization in the superconducting shield is taken into account. It is shown that our results are fully understood in terms of the fluctuating local-field interaction. Our analysis strongly supports the alternative view on the Aharonov-Bohm-Casher interference that the effects originate from the local action of electromagnetic fields.
The Aharonov-Bohm effect – where electron-interference fringe positions are shifted based on the presence of a non-local magnetic field – has not yet been utilised to its full potential in quantum device design. In this paper, we show that the de Broglie wavelength of the electron is changed locally by its interaction with the magnetic vector potential. The vector potential thus acts as a quantum “phase plate”, changing the phase difference between interfering electron wavefunctions in a non-dispersive, gauge-invariant manner. This model is then shown to be applicable to the design and optimisation of phase-dependent quantum devices such as superconducting quantum interference devices (SQUIDs), quantum sensors, and so on.
Both classical and quantum wave interference phenomena rely on the notion of phase. In both classical as well as quantum electrodynamics the phases are acquired locally; however, the quantum phases have the additional property that they can be transmitted even when the classical value of the degree of freedom relevant for the transfer (such as the value of the electric field at one point) are zero. Here we use a covariant formalism that is capable of explaining the electric and magnetic versions of the Aharonov-Bohm effect, as well as the Aharonov-Casher effect, through local interactions of charges and currents with the quantum electromagnetic field. We show that Aharonov-Bohm effect, which is just another instance of interference based on a quantum phase, is present even if the solenoid generating the magnetic field is shielded by a superconductor. This is because even though the classical value of the magnetic field is zero in the superconductor (the Meissner effect), the quantum operators pertaining to the magnetic field are non-zero and are furthermore responsible for transmitting the phase information between the solenoid and the electron. The conclusion of our work is that quantum phases cannot be shielded and we believe that this, among other consequences, finally resolves the last outstanding mystery in the Aharonov-Bohm effect.
This work studies the interference of electrons in the presence of a line of magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low temperature. It is found that, while there is a supplementary phase contribution from each electron of the mesoscopic cylinder, the sum of these individual supplementary phases is equal to zero, so that the presence of a normal-conducting mesoscopic ring at low temperature does not change the Aharonov-Bohm interference pattern of the incident electron. It is shown that it is not possible to ascertain by experimental observation that the shielding electrons have responded to the field of an incident electron, and at the same time to preserve the interference pattern of the incident electron. It is also shown that the measuring of the transient magnetic field in the region between the two paths of an electron interference experiment with an accuracy at least equal to the magnetic field of the incident electron generates a phase uncertainty which destroys the interference pattern.
This technical note gives a self-contained exposition of the Aharonov–Bohm effect, aimed at advanced undergraduate students. Starting from the role of electromagnetic potentials in classical electrodynamics, it introduces gauge freedom, the quantum Hamiltonian with minimal coupling, and the gauge covariance of the Schrödinger equation. It then derives the Aharonov–Bohm phase for both the time-dependent scalar configuration and the magnetic configuration, showing how a charged particle acquires an observable phase shift while travelling only through regions where the electromagnetic field vanishes. The final part reviews the experimental evidence, from the early electron-interference experiments of Chambers and of Möllenstedt and Bayh to the 1986 toroidal-magnet experiment of Tonomura and collaborators. In that experiment, superconducting shielding confined the magnetic flux completely and closed the leakage-field loophole, while flux quantization produced the characteristic half-fringe shift. The note is expository and pedagogical: it does not present original research results and has not been peer reviewed. Originally developed from study notes prepared for the PHYS02 scientific talk at Lady Margaret Hall, Oxford, in July 2026; an earlier version of the notes has been publicly available on GitHub since August 2026. Corrections and comments are more than welcome at giancarminesparso@gmail.com.