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We investigate operator dynamics and entanglement growth in dual-unitary circuits, a class of locally scrambled quantum systems that enables efficient simulation beyond the exponential complexity of the Hilbert space. By mapping the…

Quantum Physics · Physics 2025-04-02 Menghan Song , Zhaoyi Zeng , Ting-Tung Wang , Yi-Zhuang You , Zi Yang Meng , Pengfei Zhang

The dynamics of quantum systems unfolds within a subspace of the state space or operator space, known as the Krylov space. This review presents the use of Krylov subspace methods to provide an efficient description of quantum evolution and…

We perform quantum process tomography (QPT) for both discrete- and continuous-variable quantum systems by learning a process representation using Kraus operators. The Kraus form ensures that the reconstructed process is completely positive.…

Quantum Physics · Physics 2023-04-18 Shahnawaz Ahmed , Fernando Quijandría , Anton Frisk Kockum

We develop a method to study quantum impurity models, small interacting quantum systems linearly coupled to an environment, in presence of an additional Markovian quantum bath, with a generic non-linear coupling to the impurity. We aim at…

Quantum Physics · Physics 2025-03-10 Orazio Scarlatella , Marco Schirò

The structure of the initial system-environment state is fundamental to determining the nature and characteristics of the evolution of such an open quantum system. The usual assumption is to consider that the initial system-environment…

Quantum Physics · Physics 2017-05-17 Jad C. Halimeh , Ines de Vega

In this study, we analyze a semilinear damped evolution equation under different damping conditions, including the undamped $(\theta=0)$, effectively damped $(0<2\theta<\sigma)$, critically damped $(2\theta=\sigma)$, and non-effectively…

Analysis of PDEs · Mathematics 2025-09-03 Aparajita Dasgupta , Lalit Mohan , Abhilash Tushir

We study quantum dynamics generated by time-dependent Hamiltonians in Krylov space, the minimal subspace in which the evolution takes place. We establish a direct link between dynamics in the time-dependent Krylov subspace and the…

Quantum Physics · Physics 2026-05-18 András Grabarits , E. Medina-Guerra , Adolfo del Campo

Inevitably, assessing the overall performance of a quantum computer must rely on characterizing some of its elementary constituents and, from this information, formulate a broader statement concerning more complex constructions thereof.…

Quantum Physics · Physics 2019-08-14 Arnaud Carignan-Dugas , Matthew Alexander , Joseph Emerson

Heisenberg time evolution under a chaotic many-body Hamiltonian $H$ transforms an initially simple operator into an increasingly complex one, as it spreads over Hilbert space. Krylov complexity, or `K-complexity', quantifies this growth…

High Energy Physics - Theory · Physics 2021-06-30 E. Rabinovici , A. Sánchez-Garrido , R. Shir , J. Sonner

Keeping in view applications to numerical simulations of the evolution of a nuclear reactor core around criticality, we use a general mathematical framework for describing the evolutions of multiplicative processes (processes involving…

General Physics · Physics 2018-12-10 Bernard Gaveau , Marc-Thierry Jaekel , Jacques Maillard , Jorge Silva

We discuss the case of a Markovian master equation for an open system, as it is frequently found from environmental decoherence. We prove two theorems for the evolution of the quantum state. The first one states that for a generic initial…

Quantum Physics · Physics 2016-09-08 Lajos Diosi , Claus Kiefer

Open quantum dynamics in a tripartite scenario including a system, its environment and a passive reference is shown to resolve several open questions regarding not completely positive (NCP) dynamical maps as valid descriptions of open…

Quantum Physics · Physics 2018-04-04 Linta Joseph , Anil Shaji

We establish explicit means via which natural dilations of completely positive (CP) maps can be constructed \`a la Kraus's IInd representation theorem. To obtain this, we rely on the Choi-Jamio{\l}kowski correspondence and develop a…

Functional Analysis · Mathematics 2026-04-07 Raj Dahya

Real-time reconstruction of conditional quantum states from continuous measurement records is a fundamental requirement for quantum feedback control, yet standard stochastic master equation (SME) solvers require exact model specification,…

Machine Learning · Computer Science 2026-03-06 Priyanshi Singh , Krishna Bhatia

We study the dynamics of multiparticle Carroll-Schr\"odinger (CS) quantum systems in $1{+}1$ dimensions, where $x$ acts as the evolution variable and $t$ as the configuration coordinate. We derive the $N$-body theory on equal-$x$ slices as…

Quantum Physics · Physics 2025-12-03 José Rojas , Melvin Arias

We study a class of self-adjoint operators defined on the direct sum of two Hilbert spaces: a finite dimensional one called sometimes a ``small subsystem'' and an infinite dimensional one -- a ``reservoir''. The operator, which we call a…

Mathematical Physics · Physics 2009-11-11 Jan Derezinski , Wojciech De Roeck

We employ an $n$-replica Keldysh field theory to investigate the effects of measurements and decoherence on long distance behaviors of quantum critical states. We classify different measurements and decoherence based on their timescales and…

Quantum Physics · Physics 2023-04-18 Ruochen Ma

We investigate the dynamical evolution of quantum discord, entanglement and purity in an open quantum system of two coupled asymmetric harmonic oscillators interacting with a thermal environment. Using the Kossakowski-Lindblad master…

Quantum Physics · Physics 2026-03-25 Somayeh Mehrabankar , Farkhondeh Abbasnezhad , Davood Afshar , Aurelian Isar

We investigate the quantum correlation for tripartite entangled states in de Sitter space. First, we adopt the noisy quantum channel model. In this model, the expansion effect is represented by an operator sum representation with its…

Quantum Physics · Physics 2024-02-20 Sang-Eon Bak , Paul M. Alsing , Warner A. Miller , Shahabeddin M. Aslmarand , Doyeol Ahn

Inspired by the universal operator growth hypothesis, we extend the formalism of Krylov construction in dissipative open quantum systems connected to a Markovian bath. Our construction is based upon the modification of the Liouvillian…

Quantum Physics · Physics 2022-12-19 Aranya Bhattacharya , Pratik Nandy , Pingal Pratyush Nath , Himanshu Sahu
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