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Related papers: Siegert State Approach to Quantum Defect Theory

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A general semiclassical approach to quantum systems with system-bath interactions is developed. We study system decoherence in detail using a coherent state semiclassical wavepacket method which avoids singularity issues arising in the…

Quantum Physics · Physics 2009-11-07 Gregory A. Fiete , Eric J. Heller

We analyze the effect of decoherence, modelled by local quantum channels, on quantum critical states and we find universal properties of the resulting mixed state's entanglement, both between system and environment and within the system.…

Quantum Physics · Physics 2023-07-05 Yijian Zou , Shengqi Sang , Timothy H. Hsieh

The nonlinear positive map of density matrix of two-qubit Werner state called nonlinear channel is studied. The map of density matrix is realized by rational function. The influence of the map onto the entanglement properties of the…

Quantum Physics · Physics 2014-04-01 V. I. Man'ko , R. S. Puzko

The scattering theory of Lax and Phillips, originally developed to describe resonances associated with classical wave equations, has been recently extended to apply as well to the case of the Schroedinger equation in the case that the wave…

Quantum Physics · Physics 2009-11-10 Tamar Ben Ari , L. P. Horwitz

A new universality class distinct from the standard Wigner-Dyson ones is identified. This class is realized by putting a metallic quantum dot in contact with a superconductor, while applying a magnetic field so as to make the pairing field…

Condensed Matter · Physics 2009-10-28 Alexander Altland , Martin R. Zirnbauer

In molecular reactions at the microscopic level the appearance of resonances has an important influence on the reactivity. It is important to predict when a bound state transitions into a resonance and how these transitions depend on…

Mathematical Physics · Physics 2010-12-01 Jan Broeckhove , Przemysław Kłosiewicz , Wim Vanroose

We discuss some of the experimental motivation for the need for semigroup decay laws, and the quantum Lax-Phillips theory of scattering and unstable systems. In this framework, the decay of an unstable system is described by a semigroup.…

High Energy Physics - Theory · Physics 2011-04-15 L. P. Horwitz , Y. Strauss

The excited states of a charged particle interacting with the quantized electromagnetic field and an external potential all decay, but such a particle should have a true ground state--one that minimizes the energy and satisfies the…

Mathematical Physics · Physics 2009-10-31 Marcel Griesemer , Elliott H. Lieb , Michael Loss

We consider a model dissipative quantum-mechanical system realized by coupling a quantum oscillator to a semi-infinite classical string which serves as a means of energy transfer from the oscillator to the infinity and thus plays the role…

Other Condensed Matter · Physics 2007-05-23 E. Anisimovas , A. Matulis

In this letter, we investigate the effects of Lorentz symmetry violation on a relativistic neutral scalar boson within the framework of the Klein-Gordon formalism. We consider a tensor $(K_F)_{\mu \nu \alpha \beta}$ out of the Standard…

High Energy Physics - Theory · Physics 2025-02-19 Luis B. Castro , Antonio S. de Castro

Decoherence in many-body quantum systems can give rise to intrinsically mixed-state phases and phase transitions beyond the pure-state paradigm. Here we study the $(2+1)$D transverse-field Ising model subject to a strongly…

Quantum Physics · Physics 2026-03-26 Yi-Ming Ding , Yuxuan Guo , Zhen Bi , Zheng Yan

Transmission through potential barriers is a fundamental problem in quantum mechanics. While semiclassical methods can approximate certain aspects of transmission, they fail to capture the intrinsically quantum interference associated with…

Quantum Physics · Physics 2026-05-19 Daniel Julian Nader

We prove a theorem that shows the degeneracy of many-body states depends on total particle number and flux filling ratio, for particles in a periodic lattice and under a uniform magnetic field. Non-interacting fermions and weakly…

Quantum Gases · Physics 2010-10-27 Jian Zhang , Chao-Ming Jian , Fei Ye , Hui Zhai

We present a description of entanglement in composite quantum systems in terms of symplectic geometry. We provide a symplectic characterization of sets of equally entangled states as orbits of group actions in the space of states. In…

Mathematical Physics · Physics 2016-01-19 Adam Sawicki , Alan Huckleberry , Marek Kuś

We consider a single Rydberg atom having two degenerate levels interacting with the radiation field in a single-mode ideal cavity. The transition between the levels is carried out by a $\Lambda$-type degenerate two-photon process via a…

atom-ph · Physics 2008-02-03 N. Nayak , S. S. Hassan , T. Biswas

The relativistic problem of spinless particle subject to a Kratzer potential is analyzed. Bound state solutions for the s-wave are found by separating the Klein-Gordon equation in two parts, unlike the similar works in the literature, which…

Quantum Physics · Physics 2015-06-26 M. Kocak

It is shown that a general model for particle detection in combination with a linear application of the Wigner rotations, which correspond to momentum-dependent changes of the particle spin under Lorentz transformations, to the state of a…

Quantum Physics · Physics 2017-07-04 Pablo L. Saldanha , Vlatko Vedral

A general problem of $2\rightarrow N_f$ scattering is addressed with all the states being wave packets with arbitrary phases. Depending on these phases, one deals with coherent states in $(3+1)$ D, vortex particles with orbital angular…

High Energy Physics - Phenomenology · Physics 2017-03-13 Dmitry Karlovets

The one-dimensional Klein-Gordon equation is investigated with the most general Lorentz structure for the external potentials. The analysis and calculation of the reflection and transmission coefficients for the scattering of particles in a…

Quantum Physics · Physics 2008-11-26 Tatiana R. Cardoso , Antonio S. de Castro

The quantum state of a light beam can be represented as an infinite dimensional density matrix or equivalently as a density on the plane called the Wigner function. We describe quantum tomography as an inverse statistical problem in which…

Statistics Theory · Mathematics 2007-06-13 L. M. Artiles , R. D. Gill , M. I. Guta