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We give out the time evolution solution of simultaneous amplitude and phase damping for any continuous variable state. For the simultaneous amplitude and phase damping of a wide class of two- mode entangled Gaussian states, two analytical…

Quantum Physics · Physics 2009-11-11 Xiao-Yu Chen

Gaussian quantum states of bosonic systems are an important class of states. In particular, they play a key role in quantum optics as all processes generated by Hamiltonians up to second order in the field operators (i.e. linear optics and…

Quantum Physics · Physics 2022-03-31 Jonatan Bohr Brask

Machine learning methods have been used to infer specific properties of limited families of optical quantum states, but a unified model that predicts a broad range of properties for practically relevant-especially multimode…

Quantum Physics · Physics 2025-12-23 Xiaoting Gao , Yan Zhu , Feng-Xiao Sun , Ya-Dong Wu , Qiongyi He

Via a covariance representation based on characteristic functions, a known elementary proof of the Gaussian concentration inequality is presented. A few other applications are briefly mentioned.

Probability · Mathematics 2024-10-10 Christian Houdré

We first introduce and discuss density operator interpretations of quantum theory as a special case of a more general class of interpretations, giving special attention to a version that we call the `atomic version'. We then review some…

Quantum Physics · Physics 2007-05-23 Guido Bacciagaluppi , Michael Dickson

In this work, the operator-sum representation of a quantum process is extended to the probability representation of quantum mechanics. It is shown that each process admitting the operator-sum representation is assigned a kernel, convolving…

Quantum Physics · Physics 2022-02-03 Yan Przhiyalkovskiy

This paper is devoted to the description of the evolution of states of quantum many-particle systems within the framework of a one-particle density operator, which enables to construct the kinetic equations in scaling limits in the presence…

Mathematical Physics · Physics 2012-09-07 V. I. Gerasimenko , Zh. A. Tsvir

It is a fundamental principle of quantum theory that an unknown state cannot be copied or, as a consequence, an unknown optical signal cannot be amplified deterministically and perfectly. Here we describe a protocol that provides…

Quantum Physics · Physics 2013-11-25 Electra Eleftheriadou , Stephen M. Barnett , John Jeffers

In the paper we consider the problem of the rigorous description of the kinetic evolution in the presence of initial correlations of quantum large particle systems. One of the developed approaches consists in the description of the…

Mathematical Physics · Physics 2015-07-07 V. I. Gerasimenko

Quantum optical metrology aims to identify ultimate sensitivity bounds for the estimation of parameters encoded into quantum states of the electromagnetic field. In many practical applications, including imaging, microscopy, and remote…

Quantum Physics · Physics 2023-02-15 Giacomo Sorelli , Manuel Gessner , Nicolas Treps , Mattia Walschaers

We consider the problem of determining the state of a quantum system given one or more readings of the expectation value of an observable. The system is assumed to be a finite dimensional quantum control system for which we can influence…

Quantum Physics · Physics 2009-11-10 Domenico D'Alessandro

We investigate quantum effects in the evolution of general systems. For studying such temporal quantum phenomena, it is paramount to have a rigorous concept and profound understanding of the classical dynamics in such a system in the first…

Quantum Physics · Physics 2020-06-02 J. Sperling , I. A. Walmsley

Quantum-limited amplifiers increase the amplitude of quantum signals at the price of introducing additional noise. Quantum purification protocols operate in the reverse way, by reducing the noise while attenuating the signal. Here we…

Quantum Physics · Physics 2017-04-12 Xiaobin Zhao , Giulio Chiribella

Using Gardiner and Collet's input-output model and the concept of cascade system, we determine the filtering equation for a quantum system driven by chosen non-classical states of light. The quantum system and electromagnetic field are…

Quantum Physics · Physics 2020-02-11 Anita Dabrowska

We give a review of the tomographic probability representation of quantum mechanics. We present the formalism of quantum states and quantum observables using the formalism of standard probability distributions and classical-like random…

Quantum Physics · Physics 2020-01-29 Vladimir N. Chernega , Olga V. Man'ko , Vladimir I. Man'ko

In this tutorial, we introduce the basic concepts and mathematical tools needed for phase-space description of a very common class of states, whose phase properties are described by Gaussian Wigner functions: the Gaussian states. In…

Quantum Physics · Physics 2012-07-20 Stefano Olivares

The quantum dense output problem is the process of evaluating time-accumulated observables from time-dependent quantum dynamics using quantum computers. This problem arises frequently in applications such as quantum control and…

Quantum Physics · Physics 2024-06-21 Jin-Peng Liu , Lin Lin

The quasidistributions corresponding to the diagonal representation of quantum states are discussed within the framework of operator-symbol construction. The tomographic-probability distribution describing the quantum state in the…

Quantum Physics · Physics 2015-05-13 Vladimir I. Man'ko , Giuseppe Marmo , E. C. George Sudarshan

We give a simple demonstration that the Schr\"odinger equation may be recast as a self-contained second-order Newtonian law for a congruence of spacetime trajectories. This provides a pictorial representation of the quantum state as the…

Quantum Physics · Physics 2018-08-23 Peter Holland

Recent quantum technologies utilize complex multidimensional processes that govern the dynamics of quantum systems. We develop an adaptive diagonal-element-probing compression technique that feasibly characterizes any unknown quantum…