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Related papers: Qubit models of weak continuous measurements

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This paper is a continuation of our previous paper [8], in which we have studied the dynamics of quantum correlations of two qubits embedded each into its own disordered multiconnected environment. We modeled the environment by random…

Quantum Physics · Physics 2020-05-12 Ekaterina Bratus , Leonid Pastur

Quantum coherences are paramount resources for applications, such as quantum-enhanced light-harvesting or quantum computing, which are fragile against environmental noise. We here derive generalized quantum master equations using…

Quantum Physics · Physics 2020-09-03 Chahan M. Kropf

The very notion of a current fluctuation is problematic in the quantum context. We study that problem in the context of nonequilibrium statistical mechanics, both in a microscopic setup and in a Markovian model. Our answer is based on a…

Statistical Mechanics · Physics 2015-05-14 Jan Derezinski , Wojciech De Roeck , Christian Maes

Adaptive filtering is a powerful class of control theoretic concepts useful in extracting information from noisy data sets or performing forward prediction in time for a dynamic system. The broad utilization of the associated algorithms…

Quantum Physics · Physics 2021-07-21 Riddhi S. Gupta , Michael J. Biercuk

Quantum entanglement is affected by unitary evolution, which spreads the entanglement through the whole system, and also by measurements, which usually tends to disentangle subsystems from the rest. Their competition has been known to…

Quantum Physics · Physics 2025-06-24 Haifeng Tang , Hong-Yi Wang , Zhong Wang , Xiao-Liang Qi

We develop a dynamical framework for quantum measurement based on stochastic but unitary evolution in projective state space. Random Hamiltonians drawn from the Gaussian Unitary Ensemble generate stochastic unitary dynamics of the quantum…

Quantum Physics · Physics 2026-01-27 Alexey A. Kryukov

It has been shown that any generalized measurement can be decomposed into a sequence of weak measurements corresponding to a stochastic process. However, the weak measurements may require almost arbitrary unitaries, which are unlikely to be…

Quantum Physics · Physics 2019-08-20 Yi-Hsiang Chen , Todd A. Brun

One of the fundamental problems of quantum statistical physics is how an ideally isolated quantum system can ever reach thermal equilibrium behavior despite the unitary time evolution of quantum-mechanical systems. Here, we study, via…

Quantum Physics · Physics 2025-06-24 Marvin Lenk , Sayak Biswas , Anna Posazhennikova , Johann Kroha

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

The theoretical description of quantum dynamics in an intriguing way does not necessarily imply the underlying dynamics is indeed intriguing. Here we show how a known very interesting master equation with an always negative decay rate…

Quantum Physics · Physics 2017-07-31 Nina Megier , Dariusz Chruściński , Jyrki Piilo , Walter T. Strunz

Continuous-time stochastic processes pervade everyday experience, and the simulation of models of these processes is of great utility. Classical models of systems operating in continuous-time must typically track an unbounded amount of…

Quantum Physics · Physics 2018-03-05 Thomas J. Elliott , Mile Gu

We present a new formulation for the emergence of classical dynamics in a quantum world by considering a path integral approach that also incorporates continuous measurements. Our program is conceptually different from the decoherence…

Quantum Physics · Physics 2025-05-23 Harsh Arora , Bishal Kumar Das , Baladitya Suri , Vaibhav Madhok

The interaction between matter and squeezed light has mostly been treated within the approximation that the field correlation time is small. Methods for treating squeezed light with more general correlations currently involve explicitly…

Quantum Physics · Physics 2022-03-15 Jonathan A. Gross , Ben Baragiola , T. M. Stace , Joshua Combes

In studies of quantum squeezing, the emphasis is typically placed more on specific squeezed states and their evolution rather than on the dynamical operations that could simultaneously squeeze a broader range of quantum states, regardless…

Quantum Physics · Physics 2024-06-12 Bogdan Mielnik , Jesús Fuentes

We propose a new approach to study the evolution of a quantum state that is encoded in a system which is continuously subject to the operations required to implement a quantum error correcting code. In the limit of continuous error…

Quantum Physics · Physics 2007-05-23 Juan Pablo Paz , Wojciech Hubert Zurek

In ordinary Quantum Mechanics only ideally instantaneous observations of a quantity or a set of compatible quantities are usually considered. In an old paper of our group in Milano a formalism was introduced for the continuous monitoring of…

Quantum Physics · Physics 2015-08-27 G. M. Prosperi

We use quantum diffusive trajectories to prove that the time evolution of two-qubit entanglement under spontaneous emission can be fully characterized by optimal continuous monitoring. We analytically determine this optimal unraveling and…

The most general description of the classical world is in terms of local densities (such as number, momentum, energy), and these typically evolve according to evolution equations of hydrodynamic form. To explain the emergent classicality of…

Quantum Physics · Physics 2007-05-23 J. J. Halliwell

Quantum simulation using time evolution in phase estimation-based quantum algorithms can yield unbiased solutions of classically intractable models. However, long runtimes open such algorithms to decoherence. We show how measurement-based…

Quantum Physics · Physics 2022-08-11 Woo-Ram Lee , Zhangjie Qin , Robert Raussendorf , Eran Sela , V. W. Scarola

I propose a version of quantum mechanics featuring a discrete and finite number of states that is plausibly a model of the real world. The model is based on standard unitary quantum theory of a closed system with a finite-dimensional…

Quantum Physics · Physics 2023-11-03 Sean M. Carroll