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In this paper we build on the ideas presented in previous works for perfectly transferring a quantum state between opposite ends of a spin chain using a fixed Hamiltonian. While all previous studies have concentrated on nearest-neighbor…

Quantum Physics · Physics 2007-05-23 Alastair Kay

In this paper, we derive sharp lower bounds, also known as quantum speed limits, for the time it takes to transform a quantum system into a state such that an observable assumes its lowest average value. We assume that the system is…

Quantum Physics · Physics 2021-06-02 Dan Allan , Niklas Hörnedal , Ole Andersson

The speed limit provides an upper bound for the dynamical evolution time of a quantum system. Here, we introduce the notion of quantum acceleration limit for unitary time evolution of quantum systems under time-dependent Hamiltonian. We…

Quantum Physics · Physics 2023-12-20 Arun Kumar Pati

Manipulating quantum systems undergoing non-Gaussian dynamics in a fast and accurate manner is becoming fundamental to many quantum applications. Here, we focus on classical and quantum protocols transferring a state across a double-well…

Quantum Physics · Physics 2025-02-25 Qiongyuan Wu , Mario A. Ciampini , Mauro Paternostro , Matteo Carlesso

Tracking the time evolution of a quantum state allows one to verify the thermalization rate or the propagation speed of correlations in generic quantum systems. Inspired by the energy-time uncertainty principle, bounds have been…

Quantum speed limits provide ultimate bounds on the time required to transform one quantum state into another. Here, we extend the notion of quantum speed limits to collections of quantum states, investigating the time for converting a…

Quantum Physics · Physics 2024-04-10 Moein Naseri , Chiara Macchiavello , Dagmar Bruß , Paweł Horodecki , Alexander Streltsov

A remarkably simple result is derived for the minimal time $T_{\rm min}$ required to drive a general initial state to a final target state by a Landau-Zener type Hamiltonian or, equivalently, by time-dependent laser driving. The associated…

Quantum Physics · Physics 2015-06-16 Gerhard C. Hegerfeldt

A uniformly coupled double quantum Hamiltonian for a spin chain has recently been implemented experimentally. We propose a method for the determination of initial quantum states that will provide perfect or near-perfect state transmission…

Quantum Physics · Physics 2015-06-11 Zhao-Ming Wang , Lian-Ao Wu , C. Allen Bishop , Yong-Jian Gu , Mark S. Byrd

We propose a protocol for perfect quantum state transfer that is resilient to a broad class of realistic experimental imperfections, including noise sources that could be modelled either as independent Markovian baths or as certain forms of…

Quantum Physics · Physics 2008-07-08 C. Di Franco , M. Paternostro , D. I. Tsomokos , S. F. Huelga

Fast quantum data transmission faces several shortcomings such as the indistinguishability of some partly overlapping signals, the channel noises, and so on. Based on the encoded quantum data transmission protocol, an unconventional scheme…

Quantum Physics · Physics 2017-08-31 Weidong Tang , Sixia Yu

A general formalism of the problem of perfect state transfer is presented. We show that there are infinitely many Hamiltonians which may provide solution to this problem. In a first attempt to give a classification of them we investigate…

Quantum Physics · Physics 2007-05-23 V. Kost'ak , G. M. Nikolopoulos , I. Jex

The traditional quantum speed limits are not attainable for many physical processes, as they tend to be loose and fail to determine the exact time taken by quantum systems to evolve. To address this, we derive exact quantum speed limits for…

Quantum Physics · Physics 2023-08-30 Arun K. Pati , Brij Mohan , Sahil , Samuel L. Braunstein

We analyze the physics of optimal protocols to prepare a target state with high fidelity in a symmetrically coupled two-qubit system. By varying the protocol duration, we find a discontinuous phase transition, which is characterized by a…

Statistical Mechanics · Physics 2018-05-17 Marin Bukov , Alexandre G. R. Day , Phillip Weinberg , Anatoli Polkovnikov , Pankaj Mehta , Dries Sels

Quantum state transfer is the primitive of transporting an unknown state on one site of a lattice to another. Using power-law interactions, recent state transfer protocols achieve speedup by utilizing the intermediate ancilla sites.…

Quantum Physics · Physics 2026-02-27 Twesh Upadhyaya , Yifan Hong , T. C. Mooney , Alexey V. Gorshkov

We propose a protocol for perfect state transfer between any pair of vertices in a hypercube. Given a pair of distinct vertices in the hypercube we determine a sub-hypercube that contains the pair of vertices as antipodal vertices. Then a…

Quantum Physics · Physics 2021-01-04 Siddhant Singh , Bibhas Adhikari , Supriyo Dutta , David Zueco

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 present a method for accelerating adiabatic protocols for systems involving a coupling to a continuum, one that cancels both non-adiabatic errors as well as errors due to dissipation. We focus on applications to a generic quantum state…

Quantum Physics · Physics 2017-11-07 Alexandre Baksic , Ron Belyansky , Hugo Ribeiro , Aashish A. Clerk

In a one-dimensional Heisenberg chain, we show that there are no sets of coupling strengths such that the evolution perfectly transfers a quantum state between the two ends of the chain without the addition of magnetic fields. In lieu of…

Quantum Physics · Physics 2022-07-18 Alastair Kay

Perfect transfer of a quantum state through a one-dimensional chain is now well understood, allowing one not only to decide whether a fixed Hamiltonian achieves perfect transfer, but to design a suitable one. We are particularly interested…

Quantum Physics · Physics 2011-08-30 Alastair Kay

Faithfully transferring the quantum state is essential for quantum information processing. Here we demonstrate a fast (in 84 ns) and high-fidelity (99.2%) transfer of arbitrary quantum states in a chain of four superconducting qubits with…

Quantum Physics · Physics 2018-11-09 X. Li , Y. Ma , J. Han , Tao Chen , Y. Xu , W. Cai , H. Wang , Y. P. Song , Zheng-Yuan Xue , Zhang-qi Yin , Luyan Sun