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Related papers: A modern review of the two-level approximation

200 papers

Quantum collision models allow for the dynamics of open quantum systems to be described by breaking the environment into small segments, typically consisting of non-interacting harmonic oscillators or two-level systems. This work introduces…

Quantum Physics · Physics 2025-10-10 Anton Corr , Stefano Cusumano , Gabriele De Chiara

The exactly analytical solutions for the dynamics of the dissipative three-level V-type and $\Lambda$-type atomic systems in the vacuum Lorentzian environments are presented. Quantum interference phenomenon between the two transitions in…

Quantum Physics · Physics 2017-12-27 Hao-Sheng Zeng , Yu-Kun Ren , Zhi He

On the basis of an alternative approach to micro-cat states (Found. of Phys., 41, No. 9, p.1502 (2011)) we develop a new model of the two-slit experiment. It explains both this particular experiment and how the wave properties of any…

Quantum Physics · Physics 2015-05-30 N. L. Chuprikov

Solid state quantum bits are a promising candidate for the realization of a scalable quantum computer, however, they are usually strongly limited by decoherence. We consider a double quantum dot charge qubit, whose basis states are defined…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Udo Hartmann , Frank K. Wilhelm

Thermal light engineering is a field of considerable interest and potential. We study quantum light-matter interactions in a one-dimensional photonic crystal with two-level atoms as the active medium, replacing classical oscillators in…

Quantum Physics · Physics 2025-08-18 Chih-Wei Wang , Jhih-Sheng Wu

The thermalization of an isolated quantum system is described by quantum mechanics and thermodynamics, while these two subjects are still not fully consistent with each other. This leaves a less-explored region where both quantum and…

Quantum Gases · Physics 2024-11-22 Yuqing Wang , Libo Liang , Qinpei Zheng , Qi Huang , Wenlan Chen , Jing Zhang , Xuzong Chen , Jiazhong Hu

The aim of this review is to show how ``ferromagnetic'' states, that is, states having a fully polarization, can produce intrinsic decoherence by unitary evolution. This effect can give an understanding of recent experiments on mesoscopic…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Marco Frasca

Entangled state, as an essential tool in quantum information processing, may be generated through the interaction between light and matter in cavity quantum electrodynamics. In this paper, we study the interaction between two two-level…

Quantum Physics · Physics 2015-08-20 H. R. Baghshahi , M. K. Tavassoly , M. J. Faghihi

Multiparticle entanglement leads to richer correlations than two-particle entanglement and gives rise to striking contradictions with local realism, inequivalent classes of entanglement, and applications such as one-way or topological…

Quantum Physics · Physics 2010-12-03 J. T. Barreiro , P. Schindler , O. Gühne , T. Monz , M. Chwalla , C. F. Roos , M. Hennrich , R. Blatt

We consider the general scenario of an excited level |i> of a quantum system that can decay via two channels: (i) via a single-quantum jump to an intermediate, resonant level |bar m>, followed by a second single-quantum jump to a final…

Atomic Physics · Physics 2010-01-25 U. D. Jentschura

We consider a simple one dimensional quantum system consisting of a heavy and a light particle interacting via a point interaction. The initial state is chosen to be a product state, with the heavy particle described by a coherent…

Quantum Physics · Physics 2007-05-23 D. Duerr , R. Figari , A. Teta

We introduce an accurate non-Hermitian Schr\"odinger-type approximation of Bloch optical equations for two-level systems. This approximation provides a complete description of the excitation, relaxation and decoherence dynamics in both weak…

Quantum Physics · Physics 2016-07-11 Raiju Puthumpally-Joseph , Maxim Sukharev , Eric Charron

All physical theories should obey the second law of thermodynamics. However, existing proposals to describe the dynamics of hybrid classical-quantum systems either violate the second law or lack a proof of its existence. Here we rectify…

Quantum Physics · Physics 2025-07-29 Isaac Layton , Harry J. D. Miller

An ensemble of multilevel atoms is a good candidate for a quantum information storage device. The information is encrypted in the collective ground state atomic coherence, which, in the absence of external excitation, is decoupled from the…

Quantum Physics · Physics 2009-11-13 C. Genes , P. R. Berman

The entanglement of two dipole-coupled atoms with nondegenerate two-photon transitions interacting with two-mode field in lossless cavity has been investigated. It shows that the entanglement is dependent on the initial atomic states. The…

Quantum Physics · Physics 2012-10-16 E. K. Bashkirov , M. S. Mastuygin

Quantum coherence is a fundamental characteristic to distinguish quantum systems from their classical counterparts. Though quantum coherence persists in isolated non-interacting systems, interactions inevitably lead to decoherence, which is…

Quantum Gases · Physics 2017-11-15 Ke-Ji Chen , Ho Kwan Lau , Hon Ming Chan , Dajun Wang , Qi Zhou

We introduce the idea of weakly coherent collisional models, where the elements of an environment interacting with a system of interest are prepared in states that are approximately thermal, but have an amount of coherence proportional to a…

The nonlinear photon-photon interaction mediated by a single two-level atom is studied theoretically based on a one-dimensional model of the field-atom interaction. This model allows us to determine the effects of an atomic nonlinearity on…

Quantum Physics · Physics 2009-11-10 Kunihiro Kojima , Holger F. Hofmann , Shigeki Takeuchi , Keiji Sasaki

We find analytical solutions to the evolution of interacting two-level atoms when the master equation is symmetric under the permutation of atomic labels. The master equation includes atomic independent dissipation. The method to obtain the…

Quantum Physics · Physics 2020-08-26 W. Alvarez-Giron , P. Barberis-Blostein

This is the second paper in a cycle investigating the exact solution of loop equations in decaying turbulence. We perform numerical simulations of the Euler ensemble, suggested in the previous work, as a solution to the loop equations. We…

Fluid Dynamics · Physics 2024-03-04 Alexander Migdal