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Related papers: Quantum dynamical speedup in correlated noisy chan…

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It is generally considered that the signal output by a quantum circuit is attenuated exponentially fast in the number of gates. This letter explores how algorithms using mid-circuit measurements and classical conditioning as computational…

Quantum Physics · Physics 2024-01-05 Etienne Granet , Henrik Dreyer

We present a model of discrete quantum evolution based on quantum correlations between the evolving system and a reference quantum clock system. A quantum circuit for the model is provided, which in the case of a constant Hamiltonian is…

Quantum Physics · Physics 2016-07-06 A. Boette , R. Rossignoli , N. Gigena , M. Cerezo

Channel capacities quantify the optimal rates of sending information reliably over noisy channels. Usually, the study of capacities assumes that the circuits which sender and receiver use for encoding and decoding consist of perfectly…

Quantum Physics · Physics 2024-04-15 Paula Belzig , Matthias Christandl , Alexander Müller-Hermes

We argue that a quantum annealer at very long annealing times is likely to experience a quasistatic evolution, returning a final population that is close to a Boltzmann distribution of the Hamiltonian at a single (freeze-out) point during…

Quantum Physics · Physics 2015-11-25 Mohammad Amin

We prove fundamental rigorous bounds on the speed of quantum evolution for a quantum system coupled to a thermal bath. The bounds are formulated in terms of expectation values of few-body observables derived from the system-bath…

Quantum Physics · Physics 2024-08-20 N. Il'in , A. Aristova , O. Lychkovskiy

In a locally interacting many-body system, two isolated qubits, separated by a large distance $r$, become correlated and entangled with each other at a time $t \ge r/v$. This finite speed $v$ of quantum information scrambling limits quantum…

Quantum Physics · Physics 2019-12-25 Chi-Fang Chen , Andrew Lucas

We construct a general measure for detecting the quantum speedup in both closed and open systems. The speed measure is based on the changing rate of the position of quantum states on a manifold with appropriate monotone Riemannian metrics.…

Quantum Physics · Physics 2016-07-07 Zhen-Yu Xu

We investigate the time-evolution of quantum entanglement between an electron, liberated by a strong few-cycle laser pulse, and its parent ion-core. Since the standard procedure is numerically prohibitive in this case, we propose a novel…

Quantum Physics · Physics 2017-10-18 Szilárd Majorosi , Mihály G. Benedict , Attila Czirják

We make a thorough study of the spreading of quantum coherence (QC), as quantified by the $l_{1}$-norm QC, when a qubit (a two-level quantum system) is subjected to noise quantum channels commonly appearing in quantum information science.…

Quantum Physics · Physics 2017-02-10 Mauro B. Pozzobom , Jonas Maziero

The minimum time required for a quantum system to evolve to a distinguishable state is set by the quantum speed limit, and consequently influences the change of quantum correlations and other physical properties. Here we study the time…

We study the dynamics of quantum dissension for three qubit states in various dissipative channels such as amplitude damping, dephasing and depolarizing. Our study is solely based on Markovian environments where quantum channels are without…

Quantum Physics · Physics 2014-12-01 Pratik K. Sarangi , Indranil Chakrabarty

The minimum time a system needs to change from an initial state to a final orthogonal state is called quantum speed limit time. Quantum speed limit time can be used to quantify the speed of the quantum evolution. The speed of the quantum…

Quantum Physics · Physics 2020-06-19 S. Haseli

Entanglement is a key resource for quantum information technologies ranging from quantum sensing to quantum computing. Conventionally, the entanglement between two coupled qubits is established at the time scale of the inverse of the…

Quantum Physics · Physics 2023-09-12 Zeng-Zhao Li , Weijian Chen , Maryam Abbasi , Kater W. Murch , K. Birgitta Whaley

Quantum mechanics is an inherently linear theory. However, collective effects in many body quantum systems can give rise to effectively nonlinear dynamics. In the present work, we analyze whether and to what extent such nonlinear effects…

Quantum Physics · Physics 2022-11-23 Sebastian Deffner

Quantum annealing is a method to solve optimization problems that leverages quantum tunneling in a coupled qubit system. We present a detailed study of the coherence of a tunable capacitively-shunted flux qubit, designed for coherent…

An optimal dynamical decoupling of a quantum system coupled to a noisy environment must take into account also the imperfections of the control pulses. We present a new formalism which describes, in a closed-form expression, the evolution…

Quantum Physics · Physics 2016-10-19 Ido Almog , Gil Loewenthal , Jonathan Coslovsky , Yoav Sagi , Nir Davidson

We investigate the time evolution of entanglement for bipartite systems of arbitrary dimensions under the influence of decoherence. For qubits, we determine the precise entanglement decay rates under different system-environment couplings,…

Quantum Physics · Physics 2007-05-23 André R. R. Carvalho , Florian Mintert , Stefan Palzer , Andreas Buchleitner

Quantum entanglement is notorious for being a very fragile resource. Significant efforts have been put into the study of entanglement degradation in the presence of a realistic noisy environment. Here, we present a theoretical and an…

Quantum Physics · Physics 2019-08-21 A. Shaham , A. Halevy , L. Dovrat , E. Megidish , H. S. Eisenberg

Dual-unitary circuits are a class of locally-interacting quantum many-body systems displaying unitary dynamics also when the roles of space and time are exchanged. These systems have recently emerged as a remarkable framework where certain…

Statistical Mechanics · Physics 2023-07-04 Alessandro Foligno , Bruno Bertini

Realistic quantum computing is subjected to noise. A most important frontier in research of quantum computing is to implement noise-resilient quantum control over qubits. Dynamical decoupling can protect coherence of qubits. Here we…

Quantum Physics · Physics 2013-10-16 Gang-Qin Liu , Hoi Chun Po , Jiangfeng Du , Ren-Bao Liu , Xin-Yu Pan