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We study operators obtained by coupling an $n \times n$ random matrix from one of the Gaussian ensembles to the discrete Laplacian. We find the joint distribution of the eigenvalues and resonances of such operators. This is one of the…

Mathematical Physics · Physics 2018-01-18 Rostyslav Kozhan

Compliance control is an increasingly employed technique used in the robotic field. It is known that various mechanical properties can be reproduced depending on the design of the stiffness matrix, but the design theory that takes advantage…

Robotics · Computer Science 2022-11-01 Tsukasa Kusakabe , Sho Sakaino , Toshiaki Tsuji

Out-of-time-order correlators (OTOC) being explored as a measure of quantum chaos, is studied here in a coupled bipartite system. Each of the subsystems can be chaotic or regular and lead to very different OTOC growths both before and after…

Quantum Physics · Physics 2023-07-19 Ravi Prakash , Arul Lakshminarayan

Here, using two real non-zero parameters $\lambda$ and $\mu$, we construct Gaussian pseudo-orthogonal ensembles of a large number $N$ of $n \times n$ ($n$ even and large) real pseudo-symmetric matrices under the metric $\eta$ using $…

Quantum Physics · Physics 2025-07-15 Sachin Kumar , Amit Kumar , S M Yusuf

It is shown that, in the scaling regime, transport properties of quantum wires with off-diagonal disorder are described by a family of scaling equations that depend on two parameters: the mean free path and an additional continuous…

Disordered Systems and Neural Networks · Physics 2009-10-31 P. W. Brouwer , C. Mudry , A. Furusaki

We propose a method to study the transition to chaos in isolated quantum systems of interacting particles. It is based on the concept of delocalization of eigenstates in the energy shell, controlled by the Gaussian form of the strength…

Quantum Physics · Physics 2012-05-15 L. F. Santos , F. Borgonovi , F. M. Izrailev

The orthogonal group acts on the space of several $n\times n$ matrices by simultaneous conjugation. For an infinite field of characteristic different from two, relations between generators for the algebra of invariants are described. As an…

Representation Theory · Mathematics 2010-11-29 A. A. Lopatin

We study the dynamics and the resulting state after relaxation in a quasi-disordered integrable lattice system after a sudden quench. Specifically, we consider hard-core bosons in an isolated one-dimensional geometry in the presence of a…

Statistical Mechanics · Physics 2012-11-19 Christian Gramsch , Marcos Rigol

We investigate how quantum coherence can be distributed among the several off-diagonal elements of an arbitrary density matrix. An easily computable quantity that captures this variability notion is proposed and it is argued that it…

Quantum Physics · Physics 2026-04-24 Fernando Parisio

We consider diagonal matrix elements of local operators between multi-soliton states in finite volume in the sine-Gordon model, and formulate a conjecture regarding their finite size dependence which is valid up to corrections exponential…

High Energy Physics - Theory · Physics 2013-03-14 T. Pálmai , G. Takács

When a closed quantum system is driven periodically with period $T$, it approaches a periodic state synchronized with the drive in which any local observable measured stroboscopically approaches a steady value. For integrable systems, the…

Statistical Mechanics · Physics 2014-08-06 Achilleas Lazarides , Arnab Das , Roderich Moessner

Understanding equilibration times in closed quantum systems is essential for characterising their approach to equilibrium. Chaotic many-body systems are paradigmatic in this context: they are expected to thermalise according to the…

Fast scrambling of quantum correlations, reflected by the exponential growth of Out-of-Time-Order Correlators (OTOCs) on short pre-Ehrenfest time scales, is commonly considered as a major quantum signature of unstable dynamics in quantum…

Quantum Physics · Physics 2023-08-22 Mathias Steinhuber , Peter Schlagheck , Juan-Diego Urbina , Klaus Richter

We study matrix element fluctuations of the two-body screened Coulomb interaction and of the one-body surface charge potential in ballistic quantum dots. For chaotic dots, we use a normalized random wave model to obtain analytic expansions…

Mesoscale and Nanoscale Physics · Physics 2009-09-21 L. Kaplan , Y. Alhassid

We examine the localization properties of the Anderson Hamiltonian with additional off-diagonal disorder using the transfer-matrix method and finite-size scaling. We compute the localization lengths and study the metal-insulator transition…

Disordered Systems and Neural Networks · Physics 2015-06-24 P. Biswas , P. Cain , R. A. Roemer , M. Schreiber

We consider scenarios where the dynamics of a quantum system are partially determined by prior local measurements of some interacting environmental degrees of freedom. The resulting effective system dynamics are described by a disordered…

Quantum Physics · Physics 2024-05-06 Šárka Blahnik , Sarah Shandera

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

We study the long-time average of the reduced density matrix (RDM) of a two-level system as the central system, which is locally coupled to a generic many-body quantum chaotic system as the environment, under an overall Schr\"{o}dinger…

Quantum Physics · Physics 2020-05-14 Hua Yan , Jiaozi Wang , Wen-ge Wang

We show that the distribution of elements $H$ in the Hessian matrices associated with amorphous materials exhibit singularities $P(H) \sim {\lvert H \rvert}^{\gamma}$ with an exponent $\gamma < 0$, as $\lvert H \rvert \to 0$. We exploit the…

Disordered Systems and Neural Networks · Physics 2020-11-06 Vishnu V. Krishnan , Smarajit Karmakar , Kabir Ramola

We study operator dynamics in many-body quantum systems, focusing on generic features of systems that are ergodic, spatially extended, and lack conserved densities. Quantum circuits of various types provide simple models for such systems.…

Statistical Mechanics · Physics 2025-04-15 Takato Yoshimura , Samuel J. Garratt , J. T. Chalker