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Related papers: Gaussification through decoherence

200 papers

To quantify the effect of decoherence in quantum measurements, it is desirable to measure not merely the square modulus of the spatial wavefunction, but the entire density matrix, whose phases carry information about momentum and how pure…

Quantum Physics · Physics 2009-10-30 Max Tegmark

Quantum non-Gaussianity is a key resource for quantum advantage in continuous-variable systems. We introduce a general framework to quantify non-Gaussianity based on correlation generation: two copies of a state become correlated at a…

Quantum Physics · Physics 2025-08-28 Oliver Hahn , Ryuji Takagi

The theory of quantum information processing for macroscopic qubits is based on the fact that every macroscopic qubit has a conserved number of particles. However, from an experimental point of view, every such qubit experiences processes…

We investigate the capabilities of loss-tolerant quantum state characterization using a photon-number resolving, time-multiplexed detector (TMD). We employ the idea of probing the Wigner function point-by-point in phase space via photon…

Quantum Physics · Physics 2009-11-13 K Laiho , M Avenhaus , K N Cassemiro , Ch Silberhorn

Time evolution of the expectation values of various dynamical operators of the harmonic oscillator with dissipation is analitically obtained within the framework of the Lindblad theory for open quantum systems. We deduce the density matrix…

Quantum Physics · Physics 2007-05-23 A. Isar

We show that two-atom correlation measurements of the type involved in a recent experimental study of the evolution of a mesoscopic superposition state prepared in a definite mode of a high-Q cavity can be used to determine the eigenvalues…

Time evolution of the expectation values of various dynamical operators of the harmonic oscillator with dissipation is analitically obtained within the framework of the Lindblad's theory for open quantum systems. We deduce the density…

High Energy Physics - Theory · Physics 2007-05-23 Aurelian Isar

A gauge-invariant Wigner quantum mechanical theory is obtained by applying the Weyl-Stratonovich transform to the von Neumann equation for the density matrix. The transform reduces to the Weyl transform in the electrostatic limit, when the…

Mathematical Physics · Physics 2022-11-24 Mihail Nedjalkov , Mauro Ballicchia , Robert Kosik , Josef Weinbub

We present a quantifier of non-classical correlations for bipartite, multi-mode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in A. Farace et al., New. J. Phys. 16, 073010…

Quantum Physics · Physics 2015-11-03 Luca Rigovacca , Alessandro Farace , Antonella De Pasquale , Vittorio Giovannetti

The interplay of unitary evolution and local measurements in many-body systems gives rise to a stochastic state evolution and to measurement-induced phase transitions in the pure state entanglement. In realistic settings, however, this…

Statistical Mechanics · Physics 2022-08-23 B. Ladewig , S. Diehl , M. Buchhold

Multimode photon-subtraction provides an experimentally feasible option to construct large non-Gaussian quantum states in continuous-variable quantum optics. The non-Gaussian features of the state can lead towards the more exotic aspects of…

Quantum Physics · Physics 2019-08-28 Mattia Walschaers , Young-Sik Ra , Nicolas Treps

We derive a master equation for the reduced density matrix of a uniformly accelerating quantum detector in arbitrary dimensions, generically coupled to a field initially in its vacuum state, and analyze its late time regime. We find that…

General Relativity and Quantum Cosmology · Physics 2021-09-06 Julio Arrechea , Carlos Barceló , Luis J. Garay , Gerardo García-Moreno

By virtue of the thermal entangled states representation of density operator and using dissipative interaction picture we solve the master equation of a driven damped harmonic oscillator in a squeezed bath. We show that the essential part…

Quantum Physics · Physics 2014-02-12 Mohammad Reza Bazrafkan , Seyed Mahmoud Ashrafi , Fahimeh Naghdi

We propose a simple phenomenological model to estimate the spatial decoherence time in quantum dots. The dissipative phase space dynamics is described in terms of the density matrix and the corresponding Wigner function, which are derived…

Other Condensed Matter · Physics 2010-05-05 Michael Genkin , Erik Waltersson , Eva Lindroth

We formulate a novel approach to decoherence based on neglecting observationally inaccessible correlators. We apply our formalism to a renormalised interacting quantum field theoretical model. Using out-of-equilibrium field theory…

Quantum Physics · Physics 2015-05-27 Jurjen F. Koksma , Tomislav Prokopec , Michael G. Schmidt

We address the issue of quantifying the non-Gaussian character of a bosonic quantum state and introduce a non-Gaussianity measure based on the Hilbert-Schmidt distance between the state under examination and a reference Gaussian state. We…

Quantum Physics · Physics 2009-11-13 Marco G. Genoni , Matteo G. A. Paris , Konrad Banaszek

We calculate the quantum mechanical, temporal second-order coherence function for a single-mode, degenerate parametric amplifier for a system in the Gaussian state, viz., a displaced-squeezed thermal state. The calculation involves first…

Quantum Physics · Physics 2019-08-07 Moorad Alexanian

In paper I (Yu et al. [1]), we show through N-body simulation that a local monotonic Gaussian transformation can significantly reduce non-Gaussianity in a noise-free lensing convergence field. This makes the Gaussianization a promising…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-17 Yu Yu , Pengjie Zhang , Weipeng Lin , Weiguang Cui , James N. Fry

Non-Gaussian operations are essential to exploit the quantum advantages in optical continuous variable quantum information protocols. We focus on mode-selective photon addition and subtraction as experimentally promising processes to create…

Quantum Physics · Physics 2017-11-08 Mattia Walschaers , Claude Fabre , Valentina Parigi , Nicolas Treps

A Gaussian operator representation for the many body density matrix of fermionic systems, developed by Corney and Drummond [Phys. Rev. Lett, v93, 260401 (2004)], is used to derive approximate decoupling schemes for their dynamics. In this…

Other Condensed Matter · Physics 2009-06-01 Saar Rahav , Shaul Mukamel