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Tunneling through two vertically coupled quantum dots is studied by means of a Pauli master equation model. The observation of double peaks in the current-voltage characteristic in a recent experiment is analyzed in terms of the tunnel…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 H. Sprekeler , G. Kiesslich , A. Wacker , E. Schoell

The quantum tunneling of the magnetization vector between excited levels are studied theoretically in single-domain ferromagnetic nanoparticles with biaxial crystal symmetry placed in an external magnetic field at an arbitarily directed…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Rong Lu , Su-Peng Kou , Jia-Lin Zhu , Lee Chang , Bing-Lin Gu

The tunneling effect is the most popular phenomenon of quantum physics and is present in modern physical theories. Still, the most important features of this effect are already present in toy models - low dimensional quantum mechanics with…

Quantum Physics · Physics 2013-02-07 Zbigniew Ambrozinski

Constraints play an important role in dynamical systems. However, the subtle effect of constraints in quantum mechanics is not very well studied. In the present work we concentrate on the quantum dynamics of a point particle moving on a…

High Energy Physics - Theory · Physics 2021-02-03 Dripto Biswas , Subir Ghosh

Classical methods of differential geometry are used to construct equations of motion for particles in quantum, electrodynamic and gravitational fields. For a five dimensional geometrical system, the equivalence principle can be extended.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Daniel C. Galehouse

In this paper, macroscopic quantum tunneling (MQT) effect of Z2 topological order in the Wen-Plaquette model is studied. This kind of MQT is characterized by quantum tunneling processes of different virtual quasi-particles moving around a…

Strongly Correlated Electrons · Physics 2013-05-29 Jing Yu , Su-Peng Kou

A study of magneto-transport through quantum dots is presented. The model allows to analyze tunnelling both from bulk-like contacts and from 2D accumulation layers. The fine features in the I-V characteristics due to the quantum dot states…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 B. Jouault , M. Boero , G. Faini , J. C. Inkson

A two-level system subjected to a high-frequency driving field can exhibit an effect termed ``coherent destruction of tunneling'', in which the tunneling of the system is suppressed at certain values of the frequency and strength of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 C. E. Creffield

We calculate the one loop graviton vacuum polarization induced by a massless, nonminimally coupled scalar field on Minkowski background. We make use of the Schwinger-Keldysh formalism, which allows us to study time dependent phenomena. As…

General Relativity and Quantum Cosmology · Physics 2015-03-18 Anja Marunovic , Tomislav Prokopec

We discuss the interplay between transport and dissipation in quantum Hall bilayers. We show that quantum effects are relevant in the pseudospin picture of these systems, leading either to direct tunnelling currents or to quantum…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Robert L. Jack , Derek K. K. Lee , Nigel R. Cooper

It is conjectured that the spatial structure of quantum field states is influenced by a new kind of directional indeterminacy of quantum geometry set by the Planck length, $l_P$, that does not occur in a classical background geometry.…

General Relativity and Quantum Cosmology · Physics 2014-12-05 Craig J. Hogan

Several ways are discussed how to control the Landau-Zener tunneling in the Wannier-Stark system. We focus on a realization of this system with interacting and noninteracting ultracold bosons. The tunneling from the ground band to the…

Quantum Gases · Physics 2011-04-06 Ghazal Tayebirad , Riccardo Mannella , Sandro Wimberger

Process of quantum tunneling of particles in various physical systems can be effectively controlled even by a weak and slow varying in time electromagnetic signal if to adapt specially its shape to a particular system. During an…

Quantum Physics · Physics 2009-02-05 B. I. Ivlev

The oscillation of tunnel splitting are obtained by geometrical analysis of the topological Wess-Zumino phase on the basis of tunneling paths in biaxial nanomagnetic particles with magnetic field along the hard anisotropy axis. This theory…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sahng-Kyoon Yoo , Soo-Young Lee

Recent realization of an intense quantum light, namely bright squeezed vacuum, opened a new perspective on quantum light-matter interaction. Several theoretical works have appeared based on coherent state expansions of quantum state of…

Quantum Physics · Physics 2025-07-23 Sangwon Kim , Seongjin Ahn , Denis V. Seletskiy , Andrey S. Moskalenko

We study the dynamics of a quantum two state system driven through an avoided crossing under the influence of a super Ohmic environment, i.e. a longitudinal as well as a transversal one. The crossing time window, in which relaxation…

Quantum Physics · Physics 2021-05-11 Peter Nalbach

We review recent developments in the research of nonlinear and nonequilibrium phenomena in solids focusing on their geometrical aspects. We start with introducing the basic concepts of geometrical phases of Bloch electrons and Floquet…

Mesoscale and Nanoscale Physics · Physics 2023-06-23 Takahiro Morimoto , Sota Kitamura , Naoto Nagaosa

We present details about an experimental method based on the Landau Zener model which allows to measure very small tunnel splittings $\Delta$ in molecular clusters Fe8. The measurements are performed with an array of micro-SQUIDs. The…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 W. Wernsdorfer , R. Sessoli , A. Caneschi , D. Gatteschi , A. Cornia , D. Mailly

A quantum statistical theory of spin-dependent tunneling through asymmetric magnetic double barrier junctions is presented which describes $both$ ballistic and diffuse tunneling by a single analytical expression. It is evidenced that the…

Materials Science · Physics 2009-11-07 M. Chshiev , D. Stoeffler , A. Vedyayev , K. Ounadjela

We study the relationship between the differential conductance and the local density of states in tight-binding tunnel junctions where the junction' geometry can be varied between the point-contact and the planar-contact limits. The…

Superconductivity · Physics 2011-10-13 C. Berthod , T. Giamarchi