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Flux and symmetry effects on quantum tunneling

Helffer, Bernard ; Kachmar, Ayman LU and Sundqvist, Mikael Persson LU (2024) In Mathematische Annalen
Abstract

Motivated by the analysis of the tunneling effect for the magnetic Laplacian, we introduce an abstract framework for the spectral reduction of a self-adjoint operator to a hermitian matrix. We illustrate this framework by three applications, firstly the electro-magnetic Laplacian with constant magnetic field and three equidistant potential wells, secondly a pure constant magnetic field and Neumann boundary condition in a smoothed triangle, and thirdly a magnetic step where the discontinuity line is a smoothed triangle. Flux effects are visible in the three aforementioned settings through the occurrence of eigenvalue crossings. Moreover, in the electro-magnetic Laplacian setting with double well radial potential, we rule out an... (More)

Motivated by the analysis of the tunneling effect for the magnetic Laplacian, we introduce an abstract framework for the spectral reduction of a self-adjoint operator to a hermitian matrix. We illustrate this framework by three applications, firstly the electro-magnetic Laplacian with constant magnetic field and three equidistant potential wells, secondly a pure constant magnetic field and Neumann boundary condition in a smoothed triangle, and thirdly a magnetic step where the discontinuity line is a smoothed triangle. Flux effects are visible in the three aforementioned settings through the occurrence of eigenvalue crossings. Moreover, in the electro-magnetic Laplacian setting with double well radial potential, we rule out an artificial condition on the distance of the wells and extend the range of validity for the tunneling approximation recently established in Fefferman et al. (SIAM J Math Anal 54: 1105–1130, 2022), Helffer & Kachmar (Pure Appl Anal, 2024), thereby settling the problem of electro-magnetic tunneling under constant magnetic field and a sum of translated radial electric potentials.

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type
Contribution to journal
publication status
epub
subject
keywords
81U26
in
Mathematische Annalen
publisher
Springer
external identifiers
  • scopus:85192055526
ISSN
0025-5831
DOI
10.1007/s00208-024-02874-0
language
English
LU publication?
yes
id
2d33c3a1-5b58-4005-b741-5a301dc6ea91
date added to LUP
2024-05-21 15:27:32
date last changed
2024-05-21 15:28:45
@article{2d33c3a1-5b58-4005-b741-5a301dc6ea91,
  abstract     = {{<p>Motivated by the analysis of the tunneling effect for the magnetic Laplacian, we introduce an abstract framework for the spectral reduction of a self-adjoint operator to a hermitian matrix. We illustrate this framework by three applications, firstly the electro-magnetic Laplacian with constant magnetic field and three equidistant potential wells, secondly a pure constant magnetic field and Neumann boundary condition in a smoothed triangle, and thirdly a magnetic step where the discontinuity line is a smoothed triangle. Flux effects are visible in the three aforementioned settings through the occurrence of eigenvalue crossings. Moreover, in the electro-magnetic Laplacian setting with double well radial potential, we rule out an artificial condition on the distance of the wells and extend the range of validity for the tunneling approximation recently established in Fefferman et al. (SIAM J Math Anal 54: 1105–1130, 2022), Helffer &amp; Kachmar (Pure Appl Anal, 2024), thereby settling the problem of electro-magnetic tunneling under constant magnetic field and a sum of translated radial electric potentials.</p>}},
  author       = {{Helffer, Bernard and Kachmar, Ayman and Sundqvist, Mikael Persson}},
  issn         = {{0025-5831}},
  keywords     = {{81U26}},
  language     = {{eng}},
  publisher    = {{Springer}},
  series       = {{Mathematische Annalen}},
  title        = {{Flux and symmetry effects on quantum tunneling}},
  url          = {{http://dx.doi.org/10.1007/s00208-024-02874-0}},
  doi          = {{10.1007/s00208-024-02874-0}},
  year         = {{2024}},
}