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Related papers: Purely magnetic tunneling effect in two dimensions

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We have investigated analytically quantum tunneling of large spin in the biaxial spin system with the magnetic field applied along the hard and medium anisotropy axes by using a purely quantum-mechanical approach. When the magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Degang Zhang , Bambi Hu

In this article we revisit the observability of the Schr\"odinger equation on the two-dimensional torus. In contrast to the Schr\"odinger operator with a purely electric potential, for which any non-empty open set guarantees observability,…

Analysis of PDEs · Mathematics 2025-07-08 Kévin Le Balc'h , Jingrui Niu , Chenmin Sun

We study spin tunneling in magnetic molecules, with special reference to Fe8. The article aims to give a pedagogical discussion of what is meant by the tunneling of a spin, and how tunneling amplitudes or energy level splittings may be…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Anupam Garg

We consider the one-dimensional Schr\"{o}dinger operator in the semiclassical regime assuming that its double-well potential is the sum of a finite "physically given" well and a square shape probing well whose width or depth can be varied…

Mathematical Physics · Physics 2014-11-18 M. V. Karasev , E. V. Vybornyi

We have performed temperature dependent tunneling experiments through a single impurity in an asymmetric vertical double barrier tunneling structure. In particular in the charging direction we observe at zero magnetic field a clear shift in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. König , U. Zeitler , J. Könemann , T. Schmidt , R. J. Haug

Generalizing previous results obtained for the spectrum of the Dirichlet and Neumann realizations in a bounded domain of a Schr\"odinger operator with a purely imaginary potential $h^2\Delta+iV$ in the semiclassical limit $h\to 0$ we…

Mathematical Physics · Physics 2018-05-09 Yaniv Almog , Denis Grebenkov , Bernard Helffer

Magnetization measurements of Mn12 molecular nanomagnets with spin ground states of S = 10 and S = 19/2 showresonance tunneling at avoided energy level crossings. The observed oscillations of the tunnel probability as a function of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 W. Wernsdorfer , N. E. Chakov , G. Christou

Application of Bardeen's tunneling theory to magnetic tunnel junctions having a general degree of atomic disorder reveals the close relationship between magneto-conduction and voltage-driven pseudo-torque, as well as the thickness…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. Slonczewski

We adapt the semiclassical technique, as used in the context of instanton transitions in quantum field theory, to the description of tunneling transmissions at finite energies through potential barriers by complex quantum mechanical…

Quantum Physics · Physics 2007-05-23 G. F. Bonini , A. G. Cohen , C. Rebbi , V. A. Rubakov

In this paper we are interested in the semi-classical estimates of the spectrum of the Neumann Laplacian in dimension 3. This work aims to present a complementary case to the one presented in the paper of Helffer and Morame in the case of…

Mathematical Physics · Physics 2009-06-23 Nicolas Raymond

The presence of spin-orbit scattering within an aluminum nanoparticle affects measurements of the discrete energy levels within the particle by (1) reducing the effective g-factor below the free-electron value of 2, (2) causing avoided…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 D. G. Salinas , S. Guéron , D. C. Ralph , C. T. Black , M. Tinkham

We solve Schr\"odinger equation describing a tunneling macrospin coupled to a torsional oscillator. Energy spectrum is studied for various quantum regimes. Magnetic susceptibility and noise spectrum are computed. We show that entanglement…

Mesoscale and Nanoscale Physics · Physics 2012-01-10 D. A. Garanin , E. M. Chudnovsky

We investigate the tunneling of an electron with momentum p in the direction of V potential and under an angle {\theta} to the normal potential. Using the boundary conditions, the conditions of continuity and Snell's law, we obtain…

Quantum Physics · Physics 2014-04-25 Cassio Lima , Jorge Henrique Sales , A. T. Suzuki

We develop the concept of scattering matrix and we use it to perform stable numerical calculations of resonant tunneling of electrons through a multiple potential barrier in a semiconductor heterostructure. Electrons move in two external…

Quantum Physics · Physics 2023-07-19 J. Z. Kaminski , E. Saczuk

Denote with $\mu_{1}(\Omega;e^{h\left(|x|\right)})$ the first nontrivial eigenvalue of the Neumann problem \begin{equation*} \left\{\begin{array}{lll} -\text{div}\left(e^{h\left(|x|\right)}\nabla u\right) =\mu e^{h\left(|x|\right)}u &…

Analysis of PDEs · Mathematics 2015-02-02 F. Brock , F. Chiacchio , G. di Blasio

We establish accurate eigenvalue asymptotics and, as a by-product, sharp estimates of the splitting between two consecutive eigenvalues, for the Dirichlet magnetic Laplacian with a non-uniform magnetic field having a jump discontinuity…

Mathematical Physics · Physics 2024-03-13 Wafaa Assaad , Bernard Helffer , Ayman Kachmar

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms, calls for systematic studies of orbital effects of the magnetic field…

Strongly Correlated Electrons · Physics 2018-08-20 S. Acheche , L-F. Arsenault , A. -M. S. Tremblay

Spin tunneling in the particular case of the magnetic molecular cluster octanuclear iron(III), Fe8, is treated by an effective Hamiltonian that allows for an angle-based description of the process. The presence of an external magnetic field…

Quantum Physics · Physics 2009-11-13 D. Galetti , E. C. Silva

Starting from a phenomenological Hamiltonian originally written in terms of angular momentum operators we derive a new quantum angle-based Hamiltonian that allows for a discussion on the quantum spin tunneling. The study of the…

Quantum Physics · Physics 2007-05-23 D. Galetti

This paper is devoted to the semiclassical analysis of the spectrum of the Dirichlet-Pauli operator on an annulus. We assume that the magnetic field is strictly positive and radial. We give an explicit asymptotic expansion at the first…

Spectral Theory · Mathematics 2022-05-31 Enguerrand Lavigne Bon
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