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If frequent measurements ascertain whether a quantum system is still in its initial state, transitions to other states are hindered and the quantum Zeno effect takes place. However, in its broader formulation, the quantum Zeno effect does…

Mathematical Physics · Physics 2009-03-20 P. Facchi , S. Pascazio

The $1+1$ dimensional $\mathbb Z_2$ gauge theory is the simplest model that allows for quantum simulation to probe the fundamental aspects of a gauge theory coupled with dynamical fermions. To reliably benchmark such a system, it is crucial…

An important and incompletely answered question is whether a closed quantum system of many interacting particles can be localized by disorder. The time evolution of simple (unentangled) initial states is studied numerically for a system of…

Strongly Correlated Electrons · Physics 2012-07-11 Jens H. Bardarson , Frank Pollmann , Joel E. Moore

Characterizing how entanglement grows with time in a many-body system, for example after a quantum quench, is a key problem in non-equilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing…

Statistical Mechanics · Physics 2017-08-02 Adam Nahum , Jonathan Ruhman , Sagar Vijay , Jeongwan Haah

We study the growth and saturation of Krylov spread (K-) complexity under random quantum circuits. In Haar-random unitary evolution, we show that, for large system sizes, K-complexity grows linearly before saturating at a late-time value of…

Quantum Physics · Physics 2025-05-22 Himanshu Sahu , Aranya Bhattacharya , Pingal Pratyush Nath

We investigate the Zeno dynamics of quantum chirps. More specifically, we analyze the Zeno dynamics of a chirped solitary wave solution of the non-dimensional nonlinear Schr\"odinger equation (NLSE) with a gain/loss term. We show that the…

Quantum Physics · Physics 2021-02-03 Cihan A. Bayındır

In the context of non-relativistic quantum mechanics, we investigated Shannon's entropy of a non-Hermitian system to understand how this quantity is modified with the cyclotron frequency. Subsequently, we turn our attention to the…

Quantum Physics · Physics 2021-05-07 F. C. E. Lima , A. R. P. Moreira , C. A. S. Almeida

The entanglement dynamics in a non-Hermitian quantum system is studied numerically and analyzed from the viewpoint of quasiparticle picture. As a concrete model, we consider a one-dimensional tight-binding model with asymmetric hopping…

Quantum Physics · Physics 2023-12-15 Takahiro Orito , Ken-Ichiro Imura

For a quantum state undergoing unitary Schr\"odinger time evolution, the von Neumann entropy is constant. Yet the second law of thermodynamics, and our experience, show that entropy increases with time. Ingarden introduced the quantum…

Quantum Physics · Physics 2019-07-03 Craig S. Lent

Applying the theory of self-adjoint extensions of Hermitian operators to Koopman von Neumann classical mechanics, the most general set of probability distributions is found for which entropy is conserved by Hamiltonian evolution. A new…

Statistical Mechanics · Physics 2019-06-24 Gerard McCaul , Alexander Pechen , Denys I. Bondar

We derive the asymptotic distribution of ordinal-pattern frequencies under weak dependence conditions and investigate the long-run covariance matrix not only analytically for moving-average, Gaussian, and the novel generalized coin-tossing…

Statistics Theory · Mathematics 2025-07-24 Angelika Silbernagel , Christian Weiß

Recently, the dynamics of quantum systems that involve both unitary evolution and quantum measurements have attracted attention due to the exotic phenomenon of measurement-induced phase transitions. The latter refers to a sudden change in a…

Quantum Physics · Physics 2025-06-23 Ryotaro Suzuki , Jonas Haferkamp , Jens Eisert , Philippe Faist

We investigate some examples of quantum Zeno dynamics, when a system undergoes very frequent (projective) measurements that ascertain whether it is within a given spatial region. In agreement with previously obtained results, the evolution…

Quantum Physics · Physics 2010-01-31 P. Facchi , G. Marmo , S. Pascazio , A. Scardicchio , E. C. G. Sudarshan

Typically, scaling up the size of a system does not change the shape of its energy spectrum, other than making it denser. Exceptions, however, occur in the new phenomenon of non-Hermitian skin criticality, where closely competing…

Disordered Systems and Neural Networks · Physics 2025-11-18 Xiaoyu Cheng , Hui Jiang , Jun Chen , Lei Zhang , Yee Sin Ang , Ching Hua Lee

We provide a general dynamical approach for the quantum Zeno and anti-Zeno effects in an open quantum system under repeated non-demolition measurements. In our approach the repeated measurements are described by a general dynamical model…

Quantum Physics · Physics 2015-03-19 Peng Zhang , Qing Ai , Yong Li , D. Z. Xu , C. P. Sun

Ergodic quantum many-body systems undergoing unitary dynamics evolve towards increasingly entangled states characterized by an extensive scaling of entanglement entropy with system volume. At the other extreme, quantum systems repeatedly…

Quantum Physics · Physics 2025-03-11 Jin Ming Koh , Shi-Ning Sun , Mario Motta , Austin J. Minnich

Information-theoretic quantities such as Renyi entropies show a remarkable universality in their late-time behaviour across a variety of chaotic many-body systems. Understanding how such common features emerge from very different…

Statistical Mechanics · Physics 2026-02-02 Shreya Vardhan , Sanjay Moudgalya

Unraveling real eigenfrequencies in non-Hermitian $\mathcal{PT}$-symmetric Hamiltonians has opened new avenues in quantum physics, photonics, and most recently, phononics. However, the existing literature squarely focuses on exploiting such…

Classical Physics · Physics 2022-10-07 M. Moghaddaszadeh , M. A. Attarzadeh , A. Aref , M. Nouh

It is well known that unitary evolution tends to increase entanglement, whereas continuous monitoring counteracts this growth by pinning the wavefunction trajectories to the eigenstates of the measurement operators. In this work, we…

Statistical Mechanics · Physics 2025-07-09 Pallabi Chatterjee , Ranjan Modak

We study the unitary time evolution of the entropy of entanglement of a one-dimensional system between the degrees of freedom in an interval of length l and its complement, starting from a pure state which is not an eigenstate of the…

Statistical Mechanics · Physics 2011-02-16 Pasquale Calabrese , John Cardy