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Related papers: OTOC, complexity and entropy in bi-partite systems

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Out-of-time-ordered correlators (OTOCs), defined via the squared commutator of a time-evolving and a stationary operator, represent observables that provide useful indicators for chaos and the scrambling of information in complex quantum…

Quantum Physics · Physics 2024-10-10 Thomas R. Michel , Juan Diego Urbina , Peter Schlagheck

Out-of-time-order correlations (OTOCs) characterize the scrambling, or delocalization, of quantum information over all the degrees of freedom of a system and thus have been proposed as a proxy for chaos in quantum systems. Recent…

Quantum Physics · Physics 2018-01-30 Martin Gärttner , Philipp Hauke , Ana Maria Rey

While classical chaos has been successfully characterized with consistent theories and intuitive techniques, such as with the use of Lyapunov exponents, quantum chaos is still poorly understood, as well as its relation with multi-partite…

We establish that there are properties of quantum many-body dynamics which are efficiently learnable if we are given access to out-of-time-order correlators (OTOCs), but which require exponentially many operations in the system size if we…

Quantum Physics · Physics 2022-08-05 Jordan Cotler , Thomas Schuster , Masoud Mohseni

An extended formulation of out-of-time-ordered correlators (OTOCs), which quantify noncommutative operator growth and information scrambling in quantum many-body systems, is developed for turbulence dynamics as a representative of…

Plasma Physics · Physics 2026-02-26 Motoki Nakata

The out-of-time-ordered correlators (OTOC) and the Loschmidt echo are two measures that are now widely being explored to characterize sensitivity to perturbations and information scrambling in complex quantum systems. Studying few qubits…

Quantum Physics · Physics 2021-05-26 Sreeram PG , Vaibhav Madhok , Arul Lakshminarayan

The out-of-time ordered correlator (OTOC) is a measure of scrambling of quantum information. Scrambling is intuitively considered to be a significant feature of chaotic systems and thus the OTOC is widely used as a measure of chaos. For…

Quantum Physics · Physics 2023-06-12 Tomás Notenson , Ignacio García-Mata , Augusto J. Roncaglia , Diego A. Wisniacki

We prove a generalized fluctuation-dissipation theorem for a certain class of out-of-time-ordered correlators (OTOCs) with a modified statistical average, which we call bipartite OTOCs, for general quantum systems in thermal equilibrium.…

Statistical Mechanics · Physics 2018-02-07 Naoto Tsuji , Tomohiro Shitara , Masahito Ueda

Out-of-time-ordered-correlators (OTOCs) have been suggested as a means to diagnose chaotic behavior in quantum mechanical systems. Recently, it was found that OTOCs display exponential growth for the inverted quantum harmonic oscillator,…

High Energy Physics - Theory · Physics 2024-08-26 Paul Romatschke

We consider the time evolution of the out-of-time-ordered correlator (OTOC) of two general observables $A$ and $B$ in a mean field chaotic quantum system described by a random Wigner matrix as its Hamiltonian. We rigorously identify three…

Mathematical Physics · Physics 2024-02-28 Giorgio Cipolloni , László Erdős , Joscha Henheik

Out-of-time-order correlators (OTOCs) have proven to be a useful tool for studying thermalisation in quantum systems. In particular, the exponential growth of OTOCS, or scrambling, is sometimes taken as an indicator of chaos in quantum…

Quantum Physics · Physics 2021-03-09 R. A. Kidd , A. Safavi-Naini , J. F. Corney

The concept of out-of-time-ordered correlation (OTOC) function is treated as a very strong theoretical probe of quantum randomness, using which one can study both chaotic and non-chaotic phenomena in the context of quantum statistical…

In this paper we first compute the out-of-time-order correlators (OTOC) for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show that the OTOC decreases in power law in a many-body localized…

Quantum Gases · Physics 2017-05-12 Ruihua Fan , Pengfei Zhang , Huitao Shen , Hui Zhai

The out-of-time-ordered correlator (OTOC) is a powerful tool for probing quantum information scrambling, a fundamental process by which local information spreads irreversibly throughout a quantum many-body system. Experimentally measuring…

Quantum Physics · Physics 2026-03-18 Haruki Emori , Hiroyasu Tajima

Out-of-time-order correlators (OTOCs) have become established as a tool to characterise quantum information dynamics and thermalisation in interacting quantum many-body systems. It was recently argued that the expected exponential growth of…

Statistical Mechanics · Physics 2021-09-21 Marlon Brenes , Silvia Pappalardi , Mark T. Mitchison , John Goold , Alessandro Silva

We study observation entropy (OE) for the Quantum kicked top (QKT) model, whose classical counterpart possesses different phases: regular, mixed, or chaotic, depending on the strength of the kicking parameter. We show that OE grows…

Quantum Physics · Physics 2023-06-08 Sreeram PG , Ranjan Modak , S. Aravinda

Out-of-time-order correlator (OTOC), been suggested as a measure of quantum information scrambling in quantum many-body systems, has received enormous attention recently. The experimental measurement of OTOC is quite challenging. The…

Quantum Physics · Physics 2019-04-01 Xinfang Nie , Ze Zhang , Xiuzhu Zhao , Tao Xin , Dawei Lu , Jun Li

The out-of-time-ordered correlation (OTOC) and entanglement are two physically motivated and widely used probes of the "scrambling" of quantum information, a phenomenon that has drawn great interest recently in quantum gravity and many-body…

Quantum Physics · Physics 2021-06-16 Aram W. Harrow , Linghang Kong , Zi-Wen Liu , Saeed Mehraban , Peter W. Shor

Out-of-Time-Order-Correlator (OTOC) and Loschmidt Echo (LE) are commonly regarded as diagnostic tools for chaos, although they may yield misleading results because of various other factors. Previous studies have concluded that OTOC shows…

Quantum Physics · Physics 2025-07-01 Pranaya Pratik Das , Biplab Ganguli

Out-of time-ordered correlators (OTOC) have recently attracted significant attention from the physics of many-body systems, to quantum black-holes, with an exponential growth of the OTOC indicating quantum chaos. Here we consider OTOC in…

Quantum Physics · Physics 2019-07-03 Sivaprasad Omanakuttan , Arul Lakshminarayan