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Related papers: Quantum Filtering in Coherent States

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Several quantities of interest in quantum information, including entanglement and purity, are nonlinear functions of the density matrix and cannot, even in principle, correspond to proper quantum observables. Any method aimed to determine…

Quantum Physics · Physics 2009-08-25 Matteo G. A. Paris

In this report, we study the reduced conditional dynamics of a quantum system in the case of indirect quantum measurement. The detectors microscopic part (pointer) interacts with the measured system (target) and the environment, which…

Quantum Physics · Physics 2013-11-06 George Miroshnichenko , Alexander Trifanov

A quantum ensemble $\{(p_x, \rho_x)\}$ is a set of quantum states each occurring randomly with a given probability. Quantum ensembles are necessary to describe situations with incomplete a priori information, such as the output of a…

Quantum Physics · Physics 2009-03-30 Ognyan Oreshkov , John Calsamiglia

A key lesson of the decoherence program is that information flowing out from an open system is stored in the quantum state of the surroundings. Simultaneously, quantum measurement theory shows that the evolution of any open system when its…

Quantum Physics · Physics 2012-01-27 Juan Diego Urbina , Walter T. Strunz , Carlos Viviescas

The reliability of quantum channels for transmitting information is of profound importance from the perspective of quantum information. This naturally leads to the question as how well a quantum state is preserved when subjected to a…

Quantum Physics · Physics 2021-01-19 Javid Naikoo , Subhashish Banerjee , R. Srikanth

We derived quantum trajectories for a system interacting with the environment prepared in a continuous mode single photon state as the limit of discrete filtering model with an environment defined as series of independent qubits prepared…

Quantum Physics · Physics 2020-02-11 Anita Dabrowska , Gniewomir Sarbicki , Dariusz Chruscinski

We theoretically and experimentally investigate conditional enhancement of overall coherence of quantum states by probabilistic quantum operations that apply to the input state a quantum filter diagonal in the basis of incoherent states. We…

Quantum Physics · Physics 2021-08-03 Robert Stárek , Michal Mičuda , Michal Kolář , Radim Filip , Jaromír Fiurášek

The decay of an unstable system is usually described by an exponential law. Quantum mechanics predicts strong deviations of the survival probability from the exponential: indeed, the decay is initially quadratic, while at very large times…

Coherent states (CS) quantum entropy can be split into two components. The dynamical entropy is linked with the dynamical properties of a quantum system. The measurement entropy, which tends to zero in the semiclassical limit, describes the…

chao-dyn · Physics 2009-10-28 Jaroslaw Kwapien , Wojciech Slomczynski , Karol Zyczkowski

In this paper, we derive the stochastic master equations for quantum systems driven by a single-photon input state which is contaminated by quantum vacuum noise. To improve estimation performance, quantum filters based on multiple-channel…

Quantum Physics · Physics 2015-11-30 Zhiyuan Dong , Guofeng Zhang , Nina H. Amini

A general semiclassical approach to quantum systems with system-bath interactions is developed. We study system decoherence in detail using a coherent state semiclassical wavepacket method which avoids singularity issues arising in the…

Quantum Physics · Physics 2009-11-07 Gregory A. Fiete , Eric J. Heller

Quantum measurement theory is applied to quantum-like modeling of coherent generation of perceptions and emotions and generally for emotional coloring of conscious experiences. In quantum theory, a system should be separated from an…

Neurons and Cognition · Quantitative Biology 2021-12-08 Andrei Khrennikov

Simultaneous decoherence of conjugate observables of an open quantum system leads to a classical statistical mechanical description with constant phase space probability density in terms of a uniform ensemble. We investigate a scenario…

Quantum Physics · Physics 2026-03-30 S. Adarsh , P. N. Bala Subramanian , Sreeraj T. P

Steady-state coherence in open quantum systems is crucial for quantum technologies, yet its behavior is not fully understood due to the interplay between collective and individual decoherence. While collective decoherence is thought to…

Quantum Physics · Physics 2026-02-25 S. L. Wu , W. Ma , Zhao-Ming Wang , P. Brumer , Lian-Ao Wu

The theory of generalised measurements is used to examine the problem of discriminating unambiguously between non-orthogonal pure quantum states. Measurements of this type never give erroneous results, although, in general, there will be a…

Quantum Physics · Physics 2009-10-31 Anthony Chefles

The peculiar uncertainty or randomness of quantum measurements stems from coherence, whose information-theoretic characterization is currently under investigation. Under the resource theory of coherence, it is interesting to investigate…

Quantum Physics · Physics 2019-10-25 Xiao Yuan , Qi Zhao , Davide Girolami , Xiongfeng Ma

In the present paper I formulate a framework that accommodates many unambiguous discrimination problems. I show that the prior information about any type of constituent (state, channel, or observable) allows us to reformulate the…

Quantum Physics · Physics 2010-03-15 Michal Sedlák

Wave-particle duality and the superposition of quantum mechanical states furnish quantum mechanics with unique features which distinguishes it from classical mechanics and give it the apparently counter-intuition interpretation. The two…

Quantum Physics · Physics 2020-06-15 Abanoub Mikhail

We derive the quantum filter for a quantum open system undergoing quadrature measurements (homodyning) where the input field is in a general quasi-free state. This extends previous work for thermal input noise and allows for squeezed…

Quantum Physics · Physics 2026-05-04 John Gough , Dylon Rees

The quantum decoherence program has become more attractive in providing an acceptable solution for the long-standing quantum measurement problem. Decoherence by quantum entanglement happens very quickly to entangle the quantum system with…

Popular Physics · Physics 2023-01-04 Mani L. Bhaumik