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Related papers: Magnetic Double-Wells: Absence of Tunneling

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We present lower bounds on tunneling rates in magnetic double well systems for generic values of the coupling constant. This result was recently announced in \cite{FSW24} and complements our recent counter-example construction which…

Mathematical Physics · Physics 2025-11-18 Charles L. Fefferman , Jacob Shapiro , Michael I. Weinstein

We present new results on quantum tunneling between deep potential wells, in the presence of a strong constant magnetic field. We construct a family of double well potentials containing examples for which the low-energy eigenvalue splitting…

Mathematical Physics · Physics 2025-01-03 Charles L. Fefferman , Jacob Shapiro , Michael I. Weinstein

The two-dimensional magnetic Laplacian is considered. We calculate the leading term of the splitting between the first two eigenvalues of the operator in the semiclassical limit under the assumption that the magnetic field does not vanish…

Mathematical Physics · Physics 2025-02-25 Søren Fournais , Yannick Guedes Bonthonneau , Léo Morin , Nicolas Raymond

Inspired by a recent paper$^*$ by C. Fefferman, J. Shapiro and M. Weinstein, we investigate quantum tunneling for a Hamiltonian with a symmetric double well and a uniform magnetic field. In the simultaneous limit of strong magnetic field…

Mathematical Physics · Physics 2023-09-06 B. Helffer , A. Kachmar

We report tunneling phenomena in double In$_{0.53}$Ga$_{0.47}$As quantum-well structures that are at odds with the conventional parallel-momentum-conserving picture of tunneling between two-dimensional systems. We found that the tunneling…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Y. Lin , J. Nitta , ; A. K. M. Newaz , W. Song , E. E. Mendez

We establish a tunneling formula for a Schr\"odinger operator with symmetric double-well potential and homogeneous magnetic field, in dimension two. Each well is assumed to be radially symmetric and compactly supported. We obtain an…

Spectral Theory · Mathematics 2023-09-28 Léo Morin

In this paper, we consider the semiclassical 2D magnetic Schr{\"o}dinger operator in the case where the magnetic field vanishes along a smooth closed curve. Assuming that this curve has an axis of symmetry, we prove that semi-classical…

Mathematical Physics · Physics 2022-12-09 Khaled Abou Alfa

Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. An…

Quantum Physics · Physics 2009-11-11 B. Ivlev

Within quantum mechanics which works with parity-pseudo-Hermitian Hamiltonians we study the tunneling in a symmetric double well formed by two delta functions with complex conjugate strengths. The model is exactly solvable and exhibits…

Quantum Physics · Physics 2009-11-10 Miloslav Znojil

We investigate a Hamiltonian with radial potential wells and an Aharonov-Bohm vector potential with two poles. Assuming that the potential wells are symmetric, we derive the semi-classical asymptotics of the splitting between the ground and…

Spectral Theory · Mathematics 2024-07-24 Bernard Helffer , Ayman Kachmar

We argue that the tunneling between two 2D electron gases in a weak magnetic field is of resonance character, and involves a long lifetime excitonic state of an electron and hole {\it uniformly spread} over cyclotron orbits. We find that…

Condensed Matter · Physics 2007-05-23 L. S. Levitov , A. V. Shytov

In this paper we derive formulae for the semiclassical tunneling in the presence of a constant magnetic field in 2 dimensions. The `wells' in the problem are identical discs with Neumann boundary conditions, so we study the magnetic Neumann…

Mathematical Physics · Physics 2024-11-20 Søren Fournais , Léo Morin

We present a self-consistent approach to describe ambipolar tunneling in asymmetrical double quantum wells under steady-state excitation and extend the results to the case of tunneling from a near-surface quantum well to surface states. The…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Carlo Presilla , Valentina Emiliani , Andrea Frova

Shallow one-dimensional double well potentials appear in atomic and molecular physics and other fields. Unlike the "deep" wells of macroscopic quantum coherent systems, shallow double wells need not present low-lying two-level systems. We…

We revisit the problem of quantum tunneling for a particle moving in the continuum, and in the absence of a magnetic field. In all spatial dimensions, we extend previous results to the case where the single-well potential satisfies…

Mathematical Physics · Physics 2025-06-17 Charles L. Fefferman , Jacob Shapiro , Michael I. Weinstein

A three barrier resonant tunneling structure in which the two quantum wells are formed by a dilute magnetic semiconductor material (ZnMnSe) with a giant Zeeman splitting of the conduction band is theoretically investigated. Self-consistent…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Christian Ertler , Jaroslav Fabian

We study the full-fledged microscopic dynamics of two interacting, ultracold bosons in a one- dimensional double-well potential, through the numerically exact diagonalization of the many-body Hamiltonian. With the particles initially…

Quantum Physics · Physics 2013-05-15 Stefan Hunn , Klaus Zimmermann , Moritz Hiller , Andreas Buchleitner

An asymmetric double-well potential is considered, assuming that the minima of the wells are quadratic with a frequency $\omega$ and the difference of the minima is close to a multiple of $\hbar \omega$. A WKB wave function is constructed…

Quantum Physics · Physics 2011-04-13 Dae-Yup Song

A spin interaction Hamiltonian for topological basis is constructed in this paper. When we select proper parameters, this Hamiltonian system can be simulated by a quantum double well potential system. If the parameter $\Delta=0$, the…

Quantum Physics · Physics 2015-03-17 Gangcheng Wang , Kang Xue , Chunfang Sun , Chengcheng Zhou , Guijiao Du

A simple approximate solution for the quantum-mechanical quartic oscillator $V= m^2 x^2+g x^4$ in the double-well regime $m^2<0$ at arbitrary $g \geq 0$ is presented. It is based on a combining of perturbation theory near true minima of the…

Mathematical Physics · Physics 2015-05-13 Alexander V Turbiner
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