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Related papers: Operator Spreading in Random Unitary Circuits

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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

The vast majority of dynamical systems in classical physics are chaotic and exhibit the butterfly effect: a minute change in initial conditions can soon have exponentially large effects elsewhere. But this phenomenon is difficult to…

Quantum Physics · Physics 2020-07-06 Efim B. Rozenbaum , Leonid A. Bunimovich , Victor Galitski

Recent experimental and theoretical developments in many-body quantum systems motivate the study of their out-of-equilibrium properties through multi-time correlation functions. We consider the dynamics of higher-order out-of-time-order…

Quantum Physics · Physics 2025-06-24 Felix Fritzsch , Pieter W. Claeys

Systematic, compositional generalization beyond the training distribution remains a core challenge in machine learning -- and a critical bottleneck for the emergent reasoning abilities of modern language models. This work investigates…

Machine Learning · Computer Science 2025-10-17 Awni Altabaa , Siyu Chen , John Lafferty , Zhuoran Yang

We consider a dynamical process in a network which distributes all particles (tokens) located at a node among its neighbors, in a round-robin manner. We show that in the recurrent state of this dynamics (i.e., disregarding a polynomially…

Data Structures and Algorithms · Computer Science 2017-11-07 Adrian Kosowski , Przemysław Uznański

The out-of-time-order correlators (OTOCs) is used to study the quantum phase transitions (QPTs) between the normal phase and the superradiant phase in the Rabi and few-body Dicke models with large frequency ratio of theatomic level…

Quantum Physics · Physics 2020-02-18 Zheng-Hang Sun , Jia-Qi Cai , Qi-Cheng Tang , Yong Hu , Heng Fan

We study out-of-time-ordered correlators (OTOC) in hard-core boson models with short-range and long-range hopping and compare the results to the OTOC in the Luttinger liquid model. For the density operator, a related `commutator function'…

Strongly Correlated Electrons · Physics 2018-10-18 Cheng-Ju Lin , Olexei I. Motrunich

Scrambling and thermalisation are topics of intense study in both condensed matter and high energy physics. Random unitary dynamics form a simple testing-ground for our theoretical understanding of these processes. In this work, we derive…

Quantum Physics · Physics 2021-10-29 Ewan McCulloch

We study out-of-time-ordered correlation (OTOC) functions in various random quantum circuits and show that the average dynamics is governed by a Markovian propagator. This is then used to study relaxation of OTOC to its long-time average…

Quantum Physics · Physics 2022-04-01 Jas Bensa , Marko Znidaric

Predictive machine learning models generally excel on in-distribution data, but their performance degrades on out-of-distribution (OOD) inputs. Reliable deployment therefore requires robust OOD detection, yet this is particularly…

Machine Learning · Computer Science 2026-02-19 David Graber , Victor Armegioiu , Rebecca Buller , Siddhartha Mishra

The disorder operator, as an easily measured non-local observable, displays great potential in detecting intrinsic information of field theories. It has been systematically studied in 1d and 2d quantum systems, while the knowledge of 3d is…

Strongly Correlated Electrons · Physics 2025-10-31 Xuyang Liang , Xiao-Chuan Wu , Zenan Liu , Zhe Wang , Zheng Yan , Dao-Xin Yao

We study the spreading of initially-local operators under unitary time evolution in a 1d random quantum circuit model which is constrained to conserve a $U(1)$ charge and its dipole moment, motivated by the quantum dynamics of fracton…

Statistical Mechanics · Physics 2019-05-21 Shriya Pai , Michael Pretko , Rahul M. Nandkishore

Out-of-Time-Ordered Commutators (OTOCs), representing a key diagnostic for scrambling as a facet of short-time quantum chaos, have attracted wide-ranging interest, from many-body physics to quantum gravity. By means of a suitable form of…

Chaotic Dynamics · Physics 2025-12-24 Fabian Haneder , Gerrit Caspari , Juan Diego Urbina , Klaus Richter

In recent times out-of-time-order correlators (OTOC) have been established as a tool to understand butterfly effects, quantum information scrambling, and many-body localization. They can also be useful in determining different phases of…

Quantum Physics · Physics 2025-05-13 Rohit Kumar Shukla

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

We investigate how information spreads in three paradigmatic one-dimensional models with spatial disorder. The models we consider are unitarily related to a system of free fermions and are thus manifestly integrable. We demonstrate that…

Strongly Correlated Electrons · Physics 2019-01-23 Max McGinley , Andreas Nunnenkamp , Johannes Knolle

Out-of-time-ordered correlation functions (OTOCs) play a crucial role in the study of thermalization, entanglement, and quantum chaos, as they quantify the scrambling of quantum information due to complex interactions. As a consequence of…

The commutator between operators at different space and time has been a diagnostic for locality of unitary evolution. Most existing results are either for specific tractable (random) Hamiltonians(Out-of-Time-Order-Correlators calculations),…

Quantum Physics · Physics 2021-03-17 Chi-Fang Chen

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

We study numerically and theoretically the $d$-dimensional Hamiltonian motion of fast particles through a field of scatterers, modeled by bounded, localized, (time-dependent) potentials, that we refer to as (in)elastic non-dissipative…

Mathematical Physics · Physics 2015-05-19 B. Aguer , S. De Bièvre