English
Related papers

Related papers: Breaking the Speed Limit for Perfect Quantum State…

200 papers

We present a statistical analysis on the performance of a protocol for the faithful transfer of a quantum state in finite qubit or spin chains, in the presence of diagonal and off-diagonal disorder. It is shown that the average-state…

Quantum Physics · Physics 2013-04-10 Georgios M. Nikolopoulos

Quantum speed limits set an upper bound to the rate at which a quantum system can evolve. Adopting a phase-space approach we explore quantum speed limits across the quantum to classical transition and identify equivalent bounds in the…

Quantum Physics · Physics 2018-02-14 B. Shanahan , A. Chenu , N. Margolus , A. del Campo

When creating a quantum system whose natural dynamics provide useful computational operations, designers have two key tools at their disposal: the (constrained) choice of both the Hamiltonian and the the initial state of the system (an…

Quantum Physics · Physics 2024-04-10 Alastair Kay

We report on a time scaling technique to enhance the performances of quantum protocols in non-Hermitian systems. The considered time scaling involves no extra-couplings and yields a significant enhancement of the quantum fidelity for a…

Quantum Physics · Physics 2021-12-08 F. Impens , F. M. D'Angelis , F. A. Pinheiro , D. Guéry-Odelin

In this paper, we investigate a high-dimensional quantum state transfer protocol. An arbitrary unknown high-dimensional state can be transferred with high fidelity between two remote registers through a XX coupling spin chain of arbitrary…

Quantum Physics · Physics 2013-04-29 Wei Qin , Chuan Wang , Gui-Lu Long

The Quantum Speed Limit can be found in many different situations, in particular in the propagation of information through quantum spin chains. In homogeneous chains it implies that taking information from one extreme of the chain to the…

Quantum Physics · Physics 2020-12-30 Diego S. Acosta Coden , Sergio S. Gómez , Alejandro Ferrón , Omar Osenda

State redistribution allows one party to optimally send part of her state to another party. Here we show that this can be derived simply from two applications of coherent state-merging. This provides a protocol whereby a middle party acts…

Quantum Physics · Physics 2008-05-09 Jonathan Oppenheim

We demonstrate that the quantum communication between two parties can be significantly improved if the receiver is allowed to store the received signals in a quantum memory before decoding them. In the limit of an infinite memory, the…

Quantum Physics · Physics 2007-05-23 Vittorio Giovannetti , Daniel Burgarth

Quantum speed limits are rigorous estimates on how fast a state of a quantum system can depart from the initial state in the course of quantum evolution. Most known quantum speed limits, including the celebrated Mandelstam-Tamm and…

Quantum Physics · Physics 2021-06-02 Nikolai Il`in , Oleg Lychkovskiy

Long-distance transfer of quantum states is an indispensable part of large-scale quantum information processing. We propose a novel scheme for the transfer of two-electron entangled states, from one edge of a quantum dot array to the other…

Mesoscale and Nanoscale Physics · Physics 2019-10-22 Yue Ban , Xi Chen , Sigmund Kohler , Gloria Platero

Characterizing the most efficient evolution, the quantum speed limit (QSL) plays a significant role in quantum technology. How to generalize the well-established QSL from closed systems to open systems has attracted much attention. In…

Quantum Physics · Physics 2023-07-11 Wei Wu , Jun-Hong An

Quantum teleportation can transfer an unknown quantum state between distant quantum nodes, which holds great promise in enabling large-scale quantum networks. To advance the full potential of quantum teleportation, quantum states must be…

The goal in quantum state transfer is to avoid the need to physically transport carriers of quantum information. This is achieved by using a suitably engineered Hamiltonian that induces the transfer of the state of one subsystem to another.…

Efficient quantum-state transfer is achieved in a uniformly coupled spin-1/2 chain, with open boundaries, by application of local magnetic fields on the second and last-but-one spins, respectively. These effective \textit{barriers} induce…

Quantum Physics · Physics 2015-06-12 S. Lorenzo , T. J. G. Apollaro , A. Sindona , F. Plastina

We consider an exact state transmission, where a density matrix in one information processor A at time $t=0$ is exactly equal to that in another processor B at a later time. We demonstrate that there always exists a complete set of…

Quantum Physics · Physics 2015-05-13 Lian-Ao Wu , Yu-xi Liu , Franco Nori

Quantum mechanics establishes a fundamental bound for the minimum evolution time between two states of a given system. Known as the quantum speed limit (QSL), it is a useful tool in the context of quantum control, where the speed of some…

Quantum Physics · Physics 2013-12-25 P. M. Poggi , F. C. Lombardo , D. A. Wisniacki

The issue of quantum states' transfer -- in particular, for so-called Perfect State Transfer (PST) -- in the networks represented by the spin chains seems to be one of the major concerns in quantum computing. Especially, in the context of…

Quantum Physics · Physics 2013-02-05 Marek Sawerwain , Joanna Wiśniewska

In the absence of errors, the dynamics of a spin chain, with a suitably engineered local Hamiltonian, allow the perfect, coherent transfer of a quantum state over large distances. Here, we propose encoding and decoding procedures to recover…

Quantum Physics · Physics 2012-05-29 Chiara Marletto , Alastair Kay , Artur Ekert

We examine the role of quantum error correction (QEC) in achieving pretty good quantum state transfer over a class of $1$-d spin Hamiltonians. Recasting the problem of state transfer as one of information transmission over an underlying…

Quantum Physics · Physics 2018-11-14 Akshaya Jayashankar , Prabha Mandayam

We present several protocols for reliable quantum state transfer through a spin chain. We use a simple two-spin encoding to achieve a remarkably high fidelity transfer for an arbitrary quantum state. The fidelity of the transfer also…

Quantum Physics · Physics 2013-05-29 Zhao-Ming Wang , Mark S. Byrd , Bin Shao , Jian Zou