English
Related papers

Related papers: Decoherence of number states in phase-sensitive re…

200 papers

We present a detailed report on the decoherence of quantum states of continuous variable systems under the action of a quantum optical master equation resulting from the interaction with general Gaussian uncorrelated environments. The rate…

Quantum Physics · Physics 2007-05-23 A. Serafini , M. G. A. Paris , F. Illuminati , S. De Siena

We address the evolution of cat-like states in general Gaussian noisy channels, by considering superpositions of coherent and squeezed-coherent states coupled to an arbitrarily squeezed bath. The phase space dynamics is solved and…

Quantum Physics · Physics 2008-11-26 A. Serafini , S. De Siena , F. Illuminati , M. G. A. Paris

We study a model of dephasing (decoherence) in a two-state quantum system (qubit) coupled to a bath of harmonic oscillators. An exact analytic solution for the reduced dynamics of a two-state system in this model has been obtained…

Quantum Physics · Physics 2015-05-28 V. G. Morozov , S. Mathey , G. Röpke

A new master equation performing isotropic phase-number squeezing is suggested. The phase properties of coherent superpositions are analyzed when the state evolves in presence of a bath with fluctuations squeezed in this isotropic way. We…

Condensed Matter · Physics 2009-10-22 G. M. D'Ariano , M. Fortunato , P. Tombesi

We present a systematic study of the purity for Gaussian states of single-mode continuous variable systems. We prove the connection of purity to observable quantities for these states, and show that the joint measurement of two conjugate…

Quantum Physics · Physics 2007-05-23 M. G. A. Paris , F. Illuminati , A. Serafini , S. De Siena

We describe the decoherence process induced on a two-level quantum system in direct interaction with a non-equilibrium environment. The non-equilibrium feature is represented by a non-stationary random function corresponding to the…

Quantum Physics · Physics 2015-06-15 Fernando C. Lombardo , Paula I. Villar

We have studied the quantum dissipative problem of a Gaussian wave packet under the influence of a harmonic potential. A phenomenological approach to dissipation is adopted in the light of the well-known model in which the environment is…

Quantum Physics · Physics 2014-11-11 A. Cidrim , F. E. A. dos Santos , A. O. Caldeira

The influence of the initial preparation on dephasing in open quantum dynamics is studied using an exactly solvable model of a two-level system (qubit) interacting with a bosonic bath. It is found that for some classes of non-selective…

Quantum Physics · Physics 2015-06-11 V. V. Ignatyuk , V. G. Morozov

We study the evolution of purity, entanglement and total correlations of general two--mode Gaussian states of continuous variable systems in arbitrary uncorrelated Gaussian environments. The time evolution of purity, Von Neumann entropy,…

Quantum Physics · Physics 2007-05-23 Alessio Serafini , Fabrizio Illuminati , Matteo G. A. Paris , Silvio De Siena

Decoherence is believed to deteriorate the ability of a purification scheme that is based on the idea of driving a system to a pure state by repeatedly measuring another system in interaction with the former and hinder for a pure state to…

Quantum Physics · Physics 2008-04-23 H. Nakazato , K. Yuasa , B. Militello , A. Messina

Quantum states inevitably decay with time into a probabilistic mixture of classical states, due to their interaction with the environment and measurement instrumentation. We present the first measurement of the decoherence dynamics of…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 H. Wang , M. Hofheinz , M. Ansmann , R. C. Bialczak , Erik Lucero , M. Neeley , A. D. O'Connell , D. Sank , M. Weides , J. Wenner , A. N. Cleland , John M. Martinis

We consider unitary evolution of finite bipartite quantum systems and study time dependence of purity for initial cat states -- coherent superpositions of Gaussian wave-packets. We derive explicit formula for purity in systems with nonzero…

Quantum Physics · Physics 2009-11-11 Marko Znidaric , Tomaz Prosen

We consider the interaction of a quantum system (spin-1/2) with a macroscopic quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of harmonic oscillators. Exact solutions of the Markovian Master equation show that the…

Quantum Physics · Physics 2009-10-31 Anu Venugopalan

We study decoherence of two non-interacting qubits. The environment and its interaction with the qubits are modelled by random matrices. Decoherence, measured in terms of purity, is calculated in linear response approximation. Monte Carlo…

Quantum Physics · Physics 2007-11-22 C. Pineda , T. Gorin , T. H. Seligman

A thought experiment is discussed to clarify the concept of decoherence. Superposition of states consisting of ground state of a single hydrogen atom and its excited state after a huge amount of time is discussed to show that the…

Quantum Physics · Physics 2012-09-04 Shunichi Muto

For a system consisting of a large collection of particles, a set of variables that will generally become effectively classical are the local densities (number, momentum, energy). That is, in the context of the decoherent histories approach…

Quantum Physics · Physics 2009-10-31 J. J. Halliwell

We study spontaneous quantum coherence in an out of equilibrium system, coupled to multiple baths describing pumping and decay. For a range of parameters describing coupling to, and occupation of the baths, a stable steady-state condensed…

Superconductivity · Physics 2007-05-23 M. H. Szymanska , J. Keeling , P. B. Littlewood

We consider the qubit initial state preparation due to the nonselective measurements on an overcomplete basis, when the number of outcomes $N=3$. To be specific, we have chosen the dephasing model and applied the conditions for a…

Quantum Physics · Physics 2016-01-20 V. V. Ignatyuk

The problem investigated in this paper is einselection, i. e. the selection of mutually exclusive quantum states with definite probabilities through decoherence. Its study is based on a theory of decoherence resulting from the projection…

Quantum Physics · Physics 2009-11-10 Roland Omnes

This Letter deals with the time evolution of a qubit weakly coupled to a reservoir which has a symmetry broken state with long range order at finite temperatures. In particular, we model the ordered reservoir by a standard BCS…

Mesoscale and Nanoscale Physics · Physics 2013-04-16 Juliana Restrepo , S. Camalet , R. Chitra
‹ Prev 1 2 3 10 Next ›