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Related papers: Quantum State Reduction

200 papers

When working with quantum states, analysis of the final quantum state generated through probabilistic measurements is essential. This analysis is typically conducted by constructing the density matrix from either partial or full tomography…

Quantum Physics · Physics 2025-01-14 Rohit Prasad , Pratyay Ghosh , Ronny Thomale , Tobias Huber-Loyola

Understanding the behaviour of a quantum system coupled to its environment is of fundamental interest in the general field of quantum technologies. It also has important repercussions on foundational problems in physics, such as the process…

Quantum Physics · Physics 2021-11-01 Sapphire Lally , Nicholas Werren , Jim Al-Khalili , Andrea Rocco

Investigating the dynamics of learning in machine learning algorithms is of paramount importance for understanding how and why an approach may be successful. The tools of physics and statistics provide a robust setting for such…

High Energy Physics - Lattice · Physics 2024-12-31 Chanju Park , Matteo Favoni , Biagio Lucini , Gert Aarts

The Quasi Steady-State (QSS) model of long-term dynamics relies on the idea of time-scale decomposition. Assuming that the fast variables are infinitely fast and are stable in the long-term, the QSS model replaces the differential equations…

Systems and Control · Computer Science 2013-10-02 Xiaozhe Wang , Hsiao-Dong Chiang

We examine consequences of the density matrix approach to quantum theory in the context of a model spacetime containing closed timelike curves and find that in general, an initially pure state will evolve in a nonlinear way to a mixed…

General Relativity and Quantum Cosmology · Physics 2009-10-22 M. J. Cassidy

Non-Markovian quantum state diffusion provides a wavefunction-based framework for modeling open quantum systems. In this work, we introduce a novel machine learning approach based on an operator construction algorithm. This algorithm…

Quantum Physics · Physics 2025-09-03 Jiaji Zhang , Carlos L. Benavides-Riveros , Lipeng Chen

The purpose of this paper is to determine quantum master and filter equations for systems coupled to fields in certain non-classical continuous-mode states. Specifically, we consider two types of field states (i) single photon states, and…

Quantum Physics · Physics 2011-07-18 J. E. Gough , M. R. James , H. I. Nurdin

The Master equation describes the time evolution of the probabilities of a system with a discrete state space. This time evolution approaches for long times a stationary state that will in general depend on the initial probability…

Mathematical Physics · Physics 2022-03-09 Bernd Fernengel , Barbara Drossel

Students in quantum mechanics class are taught that the wave function contains all knowable information about an isolated system. Later in the course, this view seems to be contradicted by the mysterious density matrix, which introduces a…

General Physics · Physics 2021-04-16 Mark G. Kuzyk

A rigorous theory of quantum state reduction, the state change of the measured system caused by a measurement conditional upon the outcome of measurement, is developed fully within quantum mechanics without leading to the vicious circle…

Quantum Physics · Physics 2015-06-26 Masanao Ozawa

A formalism for quantum many-body systems is proposed through a semiclassical treatment in phase space, allowing us to establish a stochastic thermodynamics incorporating quantum statistics. Specifically, we utilize a stochastic…

Statistical Mechanics · Physics 2024-12-23 Zhaoyu Fei

A Quantum Energy Inequality (QEI) is derived for the massive Ising model, giving a state-independent lower bound on suitable averages of the energy density; the first QEI to be established for an interacting quantum field theory with…

Mathematical Physics · Physics 2015-08-13 Henning Bostelmann , Daniela Cadamuro , Christopher J. Fewster

We propose a scheme for data-driven parameterization of unresolved dimensions of dynamical systems based on the mathematical framework of quantum mechanics and Koopman operator theory. Given a system in which some components of the state…

Dynamical Systems · Mathematics 2022-08-09 David Freeman , Dimitrios Giannakis , Joanna Slawinska

Quantum state tomography is a technique in quantum information science used to reconstruct the density matrix of an unknown quantum state, providing complete information about the quantum state. It is of significant importance in fields…

Quantum Physics · Physics 2025-07-23 Wenlong Zhao , Da Zhang , Huili Zhang , Haifeng Yu , Zhang-qi Yin

We consider a toy model for the study of monitored dynamics in a many-body quantum systems. We study the stochastic Schrodinger equation resulting from the continuous monitoring with a rate $\Gamma$ of a random hermitian operator chosen at…

Statistical Mechanics · Physics 2024-07-02 Federico Gerbino , Pierre Le Doussal , Guido Giachetti , Andrea De Luca

We present a stochastic projection formalism for the description of quantum dynamics in Bosonic or spin environments. The Schr\"odinger equation in coherent state representation with respect to the environmental degrees of freedom can be…

Quantum Physics · Physics 2017-11-08 Valentin Link , Walter T. Strunz

With this work we investigate the stationary nonequilibrium density matrix of current carrying nonequilibrium steady states of in-between quantum systems that are connected to reservoirs. We describe the analytical procedure to obtain the…

Statistical Mechanics · Physics 2015-05-28 Abhishek Dhar , Keiji Saito , Peter Hanggi

A density matrix approach is developped for the control of a mixed-state quantum system using a time-dependent external field such as a train of pulses. This leads to the definition of a target density matrix constructed in a reduced…

Quantum Physics · Physics 2007-05-23 D. Sugny , A. Keller , O. Atabek , D. Daems , C. M. Dion , S. Guérin , H. R. Jauslin

A new idea for the quantization of dynamic systems, as well as space time itself, using a stochastic metric is proposed. The quantum mechanics of a mass point is constructed on a space time manifold using a stochastic metric. A stochastic…

General Relativity and Quantum Cosmology · Physics 2018-03-22 Yoshimasa Kurihara

Quantum mechanics predicts correlation between spacelike separated events which is widely argued to violate the principle of Local Causality. By contrast, here we shall show that the Schr\"odinger equation with Born's statistical…

Quantum Physics · Physics 2014-04-07 Agung Budiyono