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The evolution of two-mode Gaussian state under symmetric amplification, non-symmetric damping and thermal noise is studied. The time dependent solution of the state characteristic function is obtained. The separability criterions are given…

Quantum Physics · Physics 2009-11-13 Xiao-yu Chen , Li-zhen Jiang , Ji-wu Chen

The separability from spectrum problem asks for a characterization of the eigenvalues of the bipartite mixed states {\rho} with the property that U^*{\rho}U is separable for all unitary matrices U. This problem has been solved when the…

Quantum Physics · Physics 2014-01-17 Nathaniel Johnston

We present a theory of entanglement transformations of Gaussian pure states with local Gaussian operations and classical communication. This is the experimentally accessible set of operations that can be realized with optical elements such…

Quantum Physics · Physics 2007-05-23 G. Giedke , J. Eisert , J. I. Cirac , M. B. Plenio

For two qubits and for general bipartite quantum systems, we give a simple spectral condition in terms of the ordered eigenvalues of the density matrix which guarantees that the corresponding state is separable.

Quantum Physics · Physics 2009-11-13 M. E. Gabach Clement , G. A. Raggio

We investigate localization of entanglement of multimode Gaussian states into a pair of modes by local Gaussian measurements on the remaining modes and classical communication. We find that for pure states and for mixed symmetric states…

Quantum Physics · Physics 2009-11-13 Jaromir Fiurasek , Ladislav Mista

We study an experimental scheme to generate Gaussian two-mode entangled states via beam splitter. Specifically, we consider a nonclassical Gaussian state (squeezed state) and a thermal state as two input modes, and evaluate the degree of…

Quantum Physics · Physics 2009-11-13 Rabia Tahira , Manzoor Ikram , Hyunchul Nha , M. Suhail Zubairy

Gaussian states are of increasing interest in the estimation of physical parameters because they are easy to prepare and manipulate in experiments. In this article, we derive formulae for the optimal estimation of parameters using two- and…

Quantum Physics · Physics 2015-07-16 Dominik Šafránek , Antony R. Lee , Ivette Fuentes

Tripartite three mode Gaussian state undergoes parametric amplification and amplitude damping as well as thermal noise is studied. In the case of a state totally symmetrically interacting with the environment, the time dependent correlation…

Quantum Physics · Physics 2015-05-13 Xiao-yu Chen

Local unitary transforms cannot affect the quantum correlations between two systems sharing an entangled state although they do influence the outcomes of local measurements. By considering local squeezing operations we introduce an extended…

Quantum Physics · Physics 2023-11-15 A. Lezama , A. Auyuanet

The unavoidable interaction of quantum systems with their environment usually results in the loss of desired quantum resources. Suitably chosen system Hamiltonians, however, can, to some extent, counteract such detrimental decay, giving…

Quantum Physics · Physics 2018-10-03 Łukasz Rudnicki , Clemens Gneiting

We examine the possible states of subsystems of a system of bits or qubits. In the classical case (bits), this means the possible marginal distributions of a probability distribution on a finite number of binary variables; we give necessary…

Quantum Physics · Physics 2015-06-26 Paul Butterley , Anthony Sudbery , Jason Szulc

We consider a partial trace transformation which maps a multipartite quantum state to collection of local density matrices. We call this collection a mean field state. The necessary and sufficient conditions under which a mean field state…

Quantum Physics · Physics 2016-09-08 Sergey Bravyi

We study the relation between single-mode nonclassicality and two-mode entanglement in a beam-splitter. We show that not all of the nonclassicality (entanglement potential) is transformed into two-mode entanglement for an incident…

Quantum Physics · Physics 2015-11-30 Wenchao Ge , Mehmet Emre Tasgin , M. Suhail Zubairy

A beam splitter can generate entanglement if the input field is nonclassical, e.g. squeezed. Thus, beam splitter transformation can be utilized for obtaining single-mode nonclassicality conditions from two-mode entanglement criteria. Here,…

Quantum Physics · Physics 2020-07-13 Mehmet Emre Tasgin

We derive a simple sufficient criterion for the locality of correlations obtained from given measurements on a Gaussian quantum state. The criterion is based on the construction of a local-hidden-variable model which works by passing part…

Quantum Physics · Physics 2024-11-19 Michael G. Jabbour , Jonatan Bohr Brask

We present a novel approach to the separability problem for Gaussian quantum states of bosonic continuous variable systems. We derive a simplified necessary and sufficient separability criterion for arbitrary Gaussian states of $m$ vs $n$…

Quantum Physics · Physics 2018-02-22 Ludovico Lami , Alessio Serafini , Gerardo Adesso

We investigate localization of entanglement of multipartite mixed Gaussian states into a pair of modes by local Gaussian measurements on the remaining modes and classical communication. We provide a detailed proof that for arbitrary…

Quantum Physics · Physics 2012-08-27 Ladislav Mišta, , Jaromír Fiurášek

The entanglement criterion for continuous variable systems and the conditions under which the uncertainty relations are fulfilled are generalized to the case of a noncommutative (NC) phase-space. The quantum nature and the separability of…

Quantum multiparameter metrology is hindered by incompatibility issues, such as finding a single probe state (probe incompatibility) and a single measurement (measurement incompatibility) optimal for all parameters. The simultaneous…

We experimentally investigate the mode characteristics of multimode radiation fields propagating through frequency dependent Gaussian channels. After manipulating the twin beams emitted from a conventional parametric down-conversion source…

Quantum Physics · Physics 2015-03-17 K. Laiho , A. Christ , K. N. Cassemiro , C. Silberhorn