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

Physical review. B, Condensed matter

Model tunneling problems in a high magnetic field

Jainendra K. Jain, Steven Allan Kivelson

Published Mar 15, 1988• 56 citations
Publisher

Abstract

We have studied simple tunneling problems in two dimensions in the presence of a high transverse magnetic field both by numerical integration of the Schr\"odinger equation and by semiclassical evaluation of the path integral. We have chosen three model potentials: (i) asymmetric single well, (ii) symmetric double well, and (iii) quadruple well. We find that the semiclassical approach is analytically tractable and gives a very accurate description of the exponential and oscillatory behaviors of the tunneling matrix elements. A precise definition of the Aharonov-Bohm phase for the tunneling paths is given. In addition to the Aharonov-Bohm phase, there is also a geometrical phase coming from the fluctuation determinant, and we find that for every closed loop it is exactly \ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}.

DOI
10.1103/physrevb.37.4111

Related papers

Tunneling in a high transverse magnetic field

Jainendra K. Jain, Steven Allan Kivelson

We have studied two simple model tunneling problems involving an electron in two spatial dimensions in the presence of a high magnetic field, both by numerical integration of Schr\"odinger's equation, and by a semiclassical evaluation of the coherent-state path integral. We find that the semiclassical approach is analytically tractable and produces results in good agreement with the numerical results.

Physical Review A•Oct 1, 1987•16 citations

Tunneling in a bosonized Fermi liquid

Leonid S Levitov, A. V. Shytov

We apply the bosonization technique to the problem of tunneling in a Fermi liquid, and present a semiclassical theory of tunneling rates. To test the method, we derive and evaluate an expression for the tunneling current in the problem of two parallel Luttinger liquids. Next we study tunneling between parallel two dimensional Fermi liquids. In the absence of a magnetic field, the conductance $I/V$ has a resonance peak at zero bias. Our estimate for the peak broadening agrees with the many-body theory results. In a magnetic field perpendicular to the plane, we find a tunneling gap linear in the field, in agreement with the experiment. In this regime the tunneling is spatially coherent over a distance of the order of the cyclotron radius. The coherence can be probed by a magnetic field parallel to the plane, which gives an Aharonov-Bohm phase to the tunneling amplitude. As a result, the current is an oscillatory function of the field.

arXiv:cond-mat/9510006•Oct 2, 1995•2 citations

Thermodynamic properties of Aharonov-Bohm (AB) and magnetic fields with screened Kratzer potential

Ikot, Akpan N., Collins Okon Edet, P. O. Amadi +3 more

In this study, the Schrodinger equation (SE) with screened Kratzer potential (SKP) in the presence of external magnetic and AB-flux fields is investigated using the factorization method. The eigenvalue and eigenfunction for the system are obtained in closed form. It is found that the present of the magnetic field partially removes the degeneracy when the screening parameter of the potential was small but the addition of the AB field removed the degeneracy faster and better. The magnetization and magnetic susceptibility of the system are evaluated at zero and finite temperatures and other thermodynamic properties of the system are discussed. More so, the presence of the AB-flux field makes the system to exhibit a both a paramagnetic and diamagnetic behavior. A straight forward extension of these results to three dimension shows that the present result is consistent with those obtained in literature.

arXiv:1912.06942•Dec 14, 2019•0 citations

Quantum tunneling in deep potential wells and strong magnetic field revisited

Bernard Helffer, Ayman Kachmar

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 and deep potential wells with disjoint supports, tunneling occurs and we derive accurate estimates of its magnitude. $^*\,$[Lower bound on quantum tunneling for strong magnetic fields. SIAM J. Math. Anal. 54(1), 1105-1130 (2022).]

arXiv:2208.13030•Pure and Applied Analysis•May 16, 2024•10 citations

Fluctuations in quantum mechanics and field theories from a new version of semiclassical theory. II.

A. M. Escobar-Ruiz, Edward Shuryak, Alexander V. Turbiner

This is the second paper on the semiclassical approach based on the density matrix given by the Euclidean time path integral with fixed coinciding end points. The classical path, interpolating between this point and the classical vacuum (called a ``flucton''), as well as systematic one- and two-loop corrections were calculated in the first paper [M. A. Escobar-Ruiz, E. Shuryak, and A. V. Turbiner, Phys. Rev. D 93, 105039 (2016)] for a double-well potential. Here, we extend them for a number of quantum-mechanical problems, such as an anharmonic oscillator and the sine-Gordon potential. The method is based on a systematic expansion in Feynman diagrams and thus can be extended to quantum field theories (QFTs). We show that the loop expansion in quantum mechanics resembles the leading-log approximations in QFT. In this sequel, we present a complete set of results obtained using this method in a unified way. Alternatively, starting from the Schr\"odinger equation we derive a generalized Bloch equation whose semiclassical-like, iterative solution generates the loop expansion. We rederive the two-loop expansions for all three of the above potentials and extend them to three loops, which has not yet been done via Feynman diagrams. All results for both methods are fully consistent with each other. An asymmetric (tilted) double-well potential (nondegenerate minima) is also studied using the second method.

arXiv:1705.06159•Physical review. D/Physical review. D.•Aug 7, 2017•12 citations

Quantum tunneling in deep potential wells and strong magnetic fields revisited

Bernard Helffer, Ayman Kachmar

We investigate a Hamiltonian with a symmetric double well and a uniform magnetic field, where tunneling occurs in the simultaneous limit of strong magnetic field and deep potential wells with disjoint supports. We derive an accurate estimate of its magnitude, and obtain a precise leading order asymptoticexpression for the effect of a strong magnetic field, improving on the upper and lowerbounds established earlier by Fefferman--Shapiro--Weinstein.

•Jan 5, 2024•0 citations
We have studied simple tunneling problems in two dimensions in the presence of a high transverse magnetic field both by numerical integration of the Schr"odinger equation and by semiclassical evaluation of the path integral. We have chosen three model potentials: (i) asymmetric single well, (ii) symmetric double well, and (iii) quadruple well. We find that the semiclassical approach is analytically tractable and gives a very accurate description of the exponential and oscillatory behaviors of the tunneling matrix elements. A precise definition of the Aharonov-Bohm phase for the tunneling paths is given. In addition to the Aharonov-Bohm phase, there is also a geometrical phase coming from the fluctuation determinant, and we find that for every closed loop it is exactly \ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}.
We apply the bosonization technique to the problem of tunneling in a Fermi liquid, and present a semiclassical theory of tunneling rates. To test the method, we derive and evaluate an expression for the tunneling current in the problem of two parallel Luttinger liquids. Next we study tunneling between parallel two dimensional Fermi liquids. In the absence of a magnetic field, the conductance I/VI/VI/V has a resonance peak at zero bias. Our estimate for the peak broadening agrees with the many-body theory results. In a magnetic field perpendicular to the plane, we find a tunneling gap linear in the field, in agreement with the experiment. In this regime the tunneling is spatially coherent over a distance of the order of the cyclotron radius. The coherence can be probed by a magnetic field parallel to the plane, which gives an Aharonov-Bohm phase to the tunneling amplitude. As a result, the current is an oscillatory function of the field.
In this study, the Schrodinger equation (SE) with screened Kratzer potential (SKP) in the presence of external magnetic and AB-flux fields is investigated using the factorization method. The eigenvalue and eigenfunction for the system are obtained in closed form. It is found that the present of the magnetic field partially removes the degeneracy when the screening parameter of the potential was small but the addition of the AB field removed the degeneracy faster and better. The magnetization and magnetic susceptibility of the system are evaluated at zero and finite temperatures and other thermodynamic properties of the system are discussed. More so, the presence of the AB-flux field makes the system to exhibit a both a paramagnetic and diamagnetic behavior. A straight forward extension of these results to three dimension shows that the present result is consistent with those obtained in literature.
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 and deep potential wells with disjoint supports, tunneling occurs and we derive accurate estimates of its magnitude. ∗ ^*\,∗[Lower bound on quantum tunneling for strong magnetic fields. SIAM J. Math. Anal. 54(1), 1105-1130 (2022).]
This is the second paper on the semiclassical approach based on the density matrix given by the Euclidean time path integral with fixed coinciding end points. The classical path, interpolating between this point and the classical vacuum (called a ``flucton''), as well as systematic one- and two-loop corrections were calculated in the first paper [M. A. Escobar-Ruiz, E. Shuryak, and A. V. Turbiner, Phys. Rev. D 93, 105039 (2016)] for a double-well potential. Here, we extend them for a number of quantum-mechanical problems, such as an anharmonic oscillator and the sine-Gordon potential. The method is based on a systematic expansion in Feynman diagrams and thus can be extended to quantum field theories (QFTs). We show that the loop expansion in quantum mechanics resembles the leading-log approximations in QFT. In this sequel, we present a complete set of results obtained using this method in a unified way. Alternatively, starting from the Schr\"odinger equation we derive a generalized Bloch equation whose semiclassical-like, iterative solution generates the loop expansion. We rederive the two-loop expansions for all three of the above potentials and extend them to three loops, which has not yet been done via Feynman diagrams. All results for both methods are fully consistent with each other. An asymmetric (tilted) double-well potential (nondegenerate minima) is also studied using the second method.