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Related papers: Ergodicity in discrete-time quantum walks

200 papers

Multi-dimensional quantum walks can exhibit highly non-trivial topological structure, providing a powerful tool for simulating quantum information and transport systems. We present a flexible implementation of a 2D optical quantum walk on a…

One-parameter family of discrete-time quantum-walk models on the square lattice, which includes the Grover-walk model as a special case, is analytically studied. Convergence in the long-time limit $t \to \infty$ of all joint moments of two…

Quantum Physics · Physics 2008-06-20 Kyohei Watabe , Naoki Kobayashi , Makoto Katori , Norio Konno

We study a general class of random walks driven by a uniquely ergodic Markovian environment. Under a coupling condition on the environment we obtain strong ergodicity properties and concentration inequalities for the environment as seen…

Probability · Mathematics 2011-07-06 Frank Redig , Florian Völlering

We prove quantum ergodicity for a family of periodic Schr\"odinger operators $H$ on periodic graphs. This means that most eigenfunctions of $H$ on large finite periodic graphs are equidistributed in some sense, hence delocalized. Our…

Mathematical Physics · Physics 2022-10-27 Theo Mckenzie , Mostafa Sabri

We consider quantum walks on the cycle in the non-stationary case where the `coin' operation is allowed to change at each time step. We characterize, in algebraic terms, the set of possible state transfers and prove that, as opposed to the…

Quantum Physics · Physics 2009-11-13 Domenico D'Alessandro , Gianfranco Parlangeli , Francesca Albertini

We give a topological classification of quantum walks on an infinite 1D lattice, which obey one of the discrete symmetry groups of the tenfold way, have a gap around some eigenvalues at symmetry protected points, and satisfy a mild locality…

Quantum Physics · Physics 2018-09-10 C. Cedzich , T. Geib , F. A. Grünbaum , C. Stahl , L. Velázquez , A. H. Werner , R. F. Werner

We study Open Quantum Random Walks for which the underlying graph is a lattice, and the generators of the walk are translation-invariant. We consider the quantum trajectory associated with the OQRW, which is described by a position process…

Probability · Mathematics 2015-09-02 Raffaella Carbone , Yan Pautrat

Obtaining rigorous and general results about the non-equilibrium dynamics of extended many-body systems is a difficult task. In quantum lattice models with short-range interactions, the Lieb-Robinson bound tells us that the spatial extent…

Statistical Mechanics · Physics 2023-06-07 Dimitrios Ampelogiannis , Benjamin Doyon

In a classically chaotic system that is ergodic, any trajectory will be arbitrarily close to any point of the available phase space after a long time, filling it uniformly. Using Born's rules to connect quantum states with probabilities,…

We consider isometric actions of lattices in semisimple algebraic groups on (possibly non-compact) homogeneous spaces with (possibly infinite) invariant Radon measure. We assume that the action has a dense orbit, and demonstrate two novel…

Dynamical Systems · Mathematics 2010-09-28 Alexander Gorodnik , Amos Nevo

We consider discrete non-divergence form difference operators in a random environment and the corresponding process--the random walk in a balanced random environment in $\mathbb{Z}^d$ with a finite range of dependence. We first quantify the…

Probability · Mathematics 2022-09-30 Xiaoqin Guo , Jonathon Peterson , Hung V. Tran

We study the breaking of ergodicity measured in terms of return probability in the evolution of a quantum state of a spin chain. In the non ergodic phase a quantum state evolves in a much smaller fraction of the Hilbert space than would be…

Strongly Correlated Electrons · Physics 2013-02-28 Andrea De Luca , Antonello Scardicchio

Quantum ergodicity theorem states that for quantum systems with ergodic classical flows, eigenstates are, in average, uniformly distributed on energy surfaces. We show that if N is a hypersurface in the position space satisfying a simple…

Analysis of PDEs · Mathematics 2012-11-20 Semyon Dyatlov , Maciej Zworski

In this paper, we consider discrete time quantum walks on graphs with coin focusing on the decentralized model, where the coin operation is allowed to change with the vertex of the graph. When the coin operations can be modified at every…

Quantum Physics · Physics 2010-06-15 Francesca Albertini , Domenico D'Alessandro

We introduce a class of discrete random walk model driven by global memory effects. At any time the right-left transitions depend on the whole previous history of the walker, being defined by an urn-like memory mechanism. The characteristic…

Statistical Mechanics · Physics 2016-12-28 Adrian A. Budini

Understanding how isolated quantum many-body systems thermalize remains a central question in modern physics. We study the onset of ergodicity in a two-dimensional disordered Heisenberg Floquet model using digital quantum simulation on…

After a brief historical review of ergodicity and mixing in dynamics, particularly in quantum dynamics, we introduce definitions of quantum ergodicity and mixing using the structure of the system's energy levels and spacings. Our…

Statistical Mechanics · Physics 2016-09-07 Dongliang Zhang , H. T. Quan , Biao Wu

A discrete analog of quantum unique ergodicity was proved for Cayley graphs of quasirandom groups by Magee, Thomas and Zhao. They show that for large graphs there exist real orthonormal basis of eigenfunctions of the adjacency matrix such…

Mathematical Physics · Physics 2024-12-24 Jon Harrison , Clare Pruss

Quantum walks have emerged as an interesting alternative to the usual circuit model for quantum computing. While still universal for quantum computing, the quantum walk model has very different physical requirements, which lends itself more…

Quantum Physics · Physics 2015-05-19 Peter P. Rohde , Andreas Schreiber , Martin Stefanak , Igor Jex , Christine Silberhorn

We study one-dimensional quantum walks in a homogeneous electric field. The field is given by a phase which depends linearly on position and is applied after each step. The long time propagation properties of this system, such as revivals,…

Quantum Physics · Physics 2013-10-23 C. Cedzich , T. Rybár , A. H. Werner , A. Alberti , M. Genske , R. F. Werner