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Related papers: Quantum State Reduction

200 papers

The general idea of a stochastic gauge representation is introduced and compared with more traditional phase-space expansions, like the Wigner expansion. Stochastic gauges can be used to obtain an infinite class of positive-definite…

Soft Condensed Matter · Physics 2009-11-10 P. D. Drummond , P. Deuar

We derive the stochastic master equations, that is to say, quantum filters, and master equations for an arbitrary quantum system probed by a continuous-mode bosonic input field in two types of non-classical states. Specifically, we consider…

Quantum Physics · Physics 2012-10-17 J. E. Gough , M. R. James , H. I. Nurdin , Joshua Combes

The use of quantum stochastic models is widespread in dynamical reduction, simulation of open systems, feedback control and adaptive estimation. In many applications only part of the information contained in the filter's state is actually…

Quantum Physics · Physics 2025-10-01 Tommaso Grigoletto , Clément Pellegrini , Francesco Ticozzi

We consider a closed quantum system subject to a stochastic resetting process. The generic expression for the resulting density operator is formulated for arbitrary resetting dynamics, fully characterised by the distribution of times…

Quantum Physics · Physics 2023-02-15 Francisco J. Sevilla , Andrea Valdés-Hernández

In this article, we derive the stochastic master equations corresponding to the statistical model of a heat bath. These stochastic differential equations are obtained as continuous time limits of discrete models of quantum repeated…

Quantum Physics · Physics 2010-06-17 Ion Nechita , Clément Pellegrini

Reduced density matrices are a powerful tool in the analysis of entanglement structure, approximate or coarse-grained dynamics, decoherence, and the emergence of classicality. It is straightforward to produce a reduced density matrix with…

Quantum Physics · Physics 2020-03-09 Oleg Kabernik , Jason Pollack , Ashmeet Singh

Considering widely dispersed uncertain renewable energy sources (RESs), scenario-based stochastic optimization is an effective method for the economic dispatch of renewables-rich power systems. However, on classic computers, to simulate RES…

Optimization and Control · Mathematics 2024-04-23 Xutao Han , Zhiyi Li , Yue Xu

Using the density matrix formalism, we prove an existence theorem of the periodic steady-state for an arbitrary periodically-driven system. This state has the same period as the modulated external influence, and it is realized as an…

Atomic Physics · Physics 2016-02-17 V. I. Yudin , A. V. Taichenachev , M. Yu. Basalaev , D. Kovalenko

A quantum master equation (QME) is derived for the many-body density matrix of an open current-carrying system weakly coupled to two metal leads. The dynamics and the steady-state properties of the system for arbitrary bias are studied…

Statistical Mechanics · Physics 2016-08-31 Upendra Harbola , Massimiliano Esposito , Shaul Mukamel

In this article we propose a dynamic quantum state tomography model for qutrits subject to laser cooling. We prove that one can reduce the number of distinct measurement setups required for state reconstruction by employing the stroboscopic…

Quantum Physics · Physics 2020-07-30 Artur Czerwinski

We show that probabilities of results of all possible measurements performing on a quantum system depend on the system's state only through its density matrix. Therefore all experimentally available information about the state contains in…

Quantum Physics · Physics 2016-02-01 Alexey Nenashev

Exact and nonperturbative quantum master equation can be constructed via the calculus on path integral. It results in hierarchical equations of motion for the reduced density operator. Involved are also a set of well--defined auxiliary…

Statistical Mechanics · Physics 2015-05-13 Jian Xu , Rui-Xue Xu , YiJing Yan

The estimation of the density matrix of a $k$-level quantum system is studied when the parametrization is given by the real and imaginary part of the entries and they are estimated by independent measurements. It is established that the…

Quantum Physics · Physics 2009-11-13 D. Petz , K. M. Hangos , A. Magyar

We discuss recent findings about properties of quantum nonequilibrium steady states. In particular we focus on transport properties. It is shown that the time dependent density matrix renormalization method can be used successfully to find…

Quantum Physics · Physics 2011-11-15 Marko Znidaric

A generalization of the stochastic wave function method to quantum master equations which are not in Lindblad form is developed. The proposed stochastic unravelling is based on a description of the reduced system in a doubled Hilbert space…

Quantum Physics · Physics 2009-10-31 H. P. Breuer , B. Kappler , F. Petruccione

The simulation of quantum transport in a realistic, many-particle system is a nontrivial problem with no quantitatively satisfactory solution. While real-time propagation has the potential to overcome the shortcomings of conventional…

Mesoscale and Nanoscale Physics · Physics 2015-10-16 Justin E. Elenewski , Yanxiang Zhao , Hanning Chen

We propose a new representation for several quantum master equations in so-called quasithermodynamic form. This representation (when it exists) let one to write down dynamical equations both for diagonal and non-diagonal elements of density…

Quantum Physics · Physics 2014-08-21 E. D. Vol

We consider several observers who monitor different parts of the environment of a single quantum system and use their data to deduce its state. We derive a set of conditional stochastic master equations that describe the evolution of the…

Quantum Physics · Physics 2009-11-07 Jacek Dziarmaga , Diego A. R. Dalvit , Wojciech H. Zurek

Simulating the dynamics and the non-equilibrium steady state of an open quantum system are hard computational tasks on conventional computers. For the simulation of the time evolution, several efficient quantum algorithms have recently been…

Quantum Physics · Physics 2021-02-24 Nathan Ramusat , Vincenzo Savona

We present a method for quantum state tomography that enables the efficient estimation, with fixed precision, of any of the matrix elements of the density matrix of a state, provided that the states from the basis in which the matrix is…

Quantum Physics · Physics 2015-06-12 Ariel Bendersky , Juan Pablo Paz