English
Related papers

Related papers: Chiral Quantum Walks

200 papers

We have studied quantum systems on finite-dimensional Hilbert spaces and found that all these systems are connected through local transformations. Actually, we have shown that these transformations give rise to a gauge group that connects…

General Physics · Physics 2023-08-28 M. Caruso

High-temperature spin transport in integrable quantum spin chains exhibits a rich dynamical phase diagram, including ballistic, superdiffusive, and diffusive regimes. While integrability is known to survive in static and periodically driven…

Statistical Mechanics · Physics 2026-02-11 Songlei Wang , Chenguang Liang , Hongzheng Zhao , Zhi-Cheng Yang

The issue of irreversibility in a universe with time-reversal-symmetric laws is a central problem in physics. % , and, in particular, to statistical mechanics, information theory and quantum thermodynamics. In this letter, we discuss for…

Beginning with the principle that a closed mechanical composite system is timeless, time can be defined by the regular changes in a suitable position coordinate (clock) in the observing part, when one part of the closed composite observes…

Quantum Physics · Physics 2021-10-05 John S. Briggs

Physics takes for granted that interacting physical systems with no common history are independent, before their interaction. This principle is time-asymmetric, for no such restriction applies to systems with no common future, after an…

Quantum Physics · Physics 2007-05-23 Huw Price

Routing classical and quantum information is a fundamental task for quantum information technologies and processes. Here, we consider information encoded in the position of a quantum walker on a graph, and design an optimal structure to…

Quantum Physics · Physics 2025-04-04 Simone Cavazzoni , Giovanni Ragazzi , Paolo Bordone , Matteo G. A. Paris

In order to unitarily evolve a quantum system, an agent requires knowledge of time, a parameter which no physical clock can ever perfectly characterise. In this letter, we study how limitations on acquiring knowledge of time impact…

Quantum Physics · Physics 2023-10-24 Jake Xuereb , Florian Meier , Paul Erker , Mark T. Mitchison , Marcus Huber

A method for high-fidelity quantum state transfer in a quantum network coupled to a continuum, based on time reversal in the continuum after decay, is theoretically suggested. Provided that the energy spectrum of the network is symmetric…

Quantum Physics · Physics 2016-05-04 Stefano Longhi

We investigate two types of temporal symmetry in quantum mechanics. The first type, time symmetry, refers to the inclusion of opposite time orientations on an equivalent physical footing. The second, event symmetry, refers to the inclusion…

Quantum Physics · Physics 2023-12-22 Michael Ridley , Emily Adlam

We present a simple quantum theory of a bosonic trimer in a triangular configuration, subject to gain and loss in an open quantum systems approach. Importantly, the coupling constants between each oscillator are augmented by complex…

Mesoscale and Nanoscale Physics · Physics 2021-01-15 Charles A. Downing , David Zueco , Luis Martín-Moreno

The quantum description of time evolution in non-linear gravitational systems such as cosmological space-times is not well understood. We show, in the simplified setting of mini-superspace, that time evolution of this system can be obtained…

General Relativity and Quantum Cosmology · Physics 2023-05-02 Anne-Katherine Burns , David E. Kaplan , Tom Melia , Surjeet Rajendran

The quantum strategy (or quantum combs) framework is a useful tool for reasoning about interactions among entities that process and exchange quantum information over the course of multiple turns. We prove a time-reversal property for a…

Quantum Physics · Physics 2018-10-22 Yuan Su , John Watrous

Collapse models are modifications of quantum theory where the wave function is treated as physically real and the collapse of the wave function is a physical process. This appears to introduce a time reversal asymmetry into the dynamics of…

Quantum Physics · Physics 2015-02-25 Daniel Bedingham , Owen Maroney

Two-dimensional systems with time-dependent controls admit a quadratic Hamiltonian modelling near potential minima. Independent, dynamical normal modes facilitate inverse Hamiltonian engineering to control the system dynamics, but some…

Quantum Physics · Physics 2021-01-04 A. Tobalina , E. Torrontegui , I. Lizuain , M. Palmero , J. G. Muga

Motivated by the immense success of random walk and Markov chain methods in the design of classical algorithms, we consider_quantum_ walks on graphs. We analyse in detail the behaviour of unbiased quantum walk on the line, with the example…

Quantum Physics · Physics 2007-05-23 Ashwin Nayak , Ashvin Vishwanath

We present a theoretical study of the interaction between an atom characterized by a degenerate ground state and a reciprocal environment, such as a semiconductor nanoparticle, without the presence of external bias. Our analysis reveals…

Quantum Physics · Physics 2024-03-22 Mário G. Silveirinha , Hugo Terças , Mauro Antezza

Quantum walks are accepted as a generic model for quantum transport. The character of the transport crucially depends on the properties of the walk like its geometry and the driving coin. We demonstrate that increasing transport distance…

Quantum Physics · Physics 2020-03-25 Jan Mareš , Jaroslav Novotný , Martin Štefaňák , Igor Jex

Time reversal in quantum or classical systems described by an Hermitian Hamiltonian is a physically allowed process, which requires in principle inverting the sign of the Hamiltonian. Here we consider the problem of time reversal of a…

Quantum Physics · Physics 2017-06-29 Stefano Longhi

Efficient control of qubits plays a key role in quantum information processing. In the current work, an alternative set of differential equations are derived for an optimal quantum control of single or multiple qubits with or without…

Quantum Physics · Physics 2020-11-26 Ding Wang , Haowei Shi , Yueheng Lan

Symmetries are well known to have had a profound role in our understanding of nature and are a critical design concept for the realization of advanced technologies. In fact, many symmetry-broken states associated with different phases of…

Quantum Physics · Physics 2021-04-01 A. Sakurai , V. M. Bastidas , W. J. Munro , Kae Nemoto