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Related papers: Instantons and the quantum bound to chaos

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Scrambling of information in a quantum many-body system, quantified by the out-of-time-ordered correlator (OTOC), is a key manifestation of quantum chaos. A regime of exponential growth in the OTOC, characterized by a Lyapunov exponent, has…

Strongly Correlated Electrons · Physics 2021-03-24 Anna Keselman , Laimei Nie , Erez Berg

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

Discretizing the $\lambda \phi^4$ scalar field theory on a lattice yields a system of coupled anharmonic oscillators with quadratic and quartic potentials. We begin by analyzing the two coupled oscillators in the second quantization method…

High Energy Physics - Theory · Physics 2026-05-12 Wung-Hong Huang

Focusing on semiclassical systems, we show that the parametrically long exponential growth of out-of-time order correlators (OTOCs), also known as scrambling, does not necessitate chaos. Indeed, scrambling can simply result from the…

Statistical Mechanics · Physics 2020-04-09 Tianrui Xu , Thomas Scaffidi , Xiangyu Cao

Out-of-time-ordered correlators (OTOC) have been proposed to characterize quantum chaos in generic systems. However, they can also show interesting behavior in integrable models, resembling the OTOC in chaotic systems in some aspects. Here…

Statistical Mechanics · Physics 2018-04-25 Cheng-Ju Lin , Olexei I. Motrunich

The out-of-time-ordered correlator (OTOC) is central to the understanding of information scrambling in quantum many-body systems. In this work, we show that the OTOC in a quantum many-body system close to its critical point obeys dynamical…

Quantum Physics · Physics 2019-11-13 Bo-Bo Wei , Gaoyong Sun , Myung-Joong Hwang

We explore the quantum chaos of the coadjoint orbit action. We study quantum fluctuation around a saddle point to evaluate the soft mode contribution to the out-of-time-ordered correlator. We show that the stability condition of the…

High Energy Physics - Theory · Physics 2021-11-15 Junggi Yoon

In this note we study chaos in generic quantum systems with a global symmetry generalizing seminal work [arXiv : 1503.01409] by Maldacena, Shenker and Stanford. We conjecture a bound on instantaneous chaos exponent in a thermodynamic…

High Energy Physics - Theory · Physics 2019-10-23 Indranil Halder

Out-of-Time-Order Correlators (OTOCs) serve as a proxy for quantum information scrambling, which refers to the process where information stored locally disperses across the many-body degrees of freedom in a quantum system, rendering it…

Out-of-time-order correlators (OTOC) are considered to be a promising tool to characterize chaos in quantum systems. In this paper we study OTOC in XY model. With the presence of anisotropic parameter $\gamma$ and external magnetic field…

Statistical Mechanics · Physics 2020-08-26 Jiahui Bao , Cheng-Yong Zhang

We investigate the onset of chaos in a periodically kicked Dicke model (KDM), using the out-of-time-order correlator (OTOC) as a diagnostic tool, in both the oscillator and the spin subspaces. In the large spin limit, the classical…

Statistical Mechanics · Physics 2021-04-26 Sudip Sinha , Sayak Ray , Subhasis Sinha

The out-of-time-order correlator (OTOC) quantifies information scrambling in quantum systems and serves as a key diagnostic of quantum chaos. In one-body systems with a classical counterpart, the relaxation of the OTOC is governed by…

Quantum Physics · Physics 2026-03-03 Jerónimo Duarte , Ignacio García-Mata , Diego A. Wisniacki

Using the parametric representation of a chaotic many-body quantum system derived earlier, we calculate explicitly the large-time dependence and asymptotic value of the out-of-time correlator (OTOC) of that system. The dependence on time…

Mathematical Physics · Physics 2025-05-12 Hans A. Weidenmüller

A fundamental result in modern quantum chaos theory is the Maldacena-Shenker-Stanford upper bound on the growth of out-of-time-order correlators, whose infinite-temperature limit is related to the operator-space entanglement entropy of the…

Quantum Physics · Physics 2021-04-20 Zongping Gong , Lorenzo Piroli , J. Ignacio Cirac

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

Out-of-time-ordered correlators (OTOC) are a quantifier of quantum information scrambling and quantum chaos. We propose an efficient quantum algorithm to measure OTOCs that provides an exponential speed-up over the best known classical…

Quantum Physics · Physics 2021-03-17 Sreeram PG , Naga Dileep Varikuti , Vaibhav Madhok

In this study, we investigate out-of-time-order correlators (OTOCs) in systems with power-law decaying interactions such as $R^{-\alpha}$, where $R$ is the distance. In such systems, the fast scrambling of quantum information or the…

Quantum Physics · Physics 2021-01-29 Tomotaka Kuwahara , Keiji Saito

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

Out-of-time-order correlators (OTOCs) are a standard measure of quantum chaos. Of the four operators involved, one pair may be regarded as a source and the other as a probe. A usual approach, applicable to large-$N$ systems such as the SYK…

High Energy Physics - Theory · Physics 2022-03-24 Yingfei Gu , Alexei Kitaev , Pengfei Zhang

We investigate the dynamics of the out-of-time-ordered correlators (OTOCs) via a non-Hermitian extension of the quantum kicked rotor model, where the kicking potential satisfies $\mathcal{PT}$-symmetry. The spontaneous $\cal{PT}$-symmetry…

Quantum Physics · Physics 2022-12-20 Wen-Lei Zhao , Ru-Ru Wang