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Related papers: Interaction cost of non-local gates

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The task of non-local quantum computation requires implementation of a unitary on $n$ qubits between two parties with only one round of communication, ideally with minimal pre-shared entanglement. We introduce a new protocol that makes use…

Quantum Physics · Physics 2022-06-02 Kfir Dolev , Sam Cree

The construction of two-qubit gates appropriate for universal quantum computation is of enormous importance to quantum information processing. Building such gates is dependent on accurate knowledge of the interaction dynamics between two…

Quantum Physics · Physics 2009-11-11 Simon J. Devitt , Jared H. Cole , Lloyd C. L. Hollenberg

We show that a wide range of spin clusters with antiferromagnetic intracluster exchange interaction allows one to define a qubit. For these spin cluster qubits, initialization, quantum gate operation, and readout are possible using the same…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Florian Meier , Jeremy Levy , Daniel Loss

Multipartite quantum correlated systems (MQCSs) are widely utilized in diverse quantum information tasks, where their sophisticated control inherently incurs energetic costs. However, the fundamental characteristics of these control costs…

Quantum Physics · Physics 2025-06-23 Rui Guan , Junjie Liu , Jian-Hua Jiang

Quantum nonlocality concerns correlations among spatially separated systems that cannot be classically explained without post-measurement communication among the parties. Thus, a natural measure of nonlocal correlations is provided by the…

Quantum Physics · Physics 2016-02-26 Alberto Montina , Stefan Wolf

Most quantum computer realizations require the ability to apply local fields and tune the couplings between qubits, in order to realize single bit and two bit gates which are necessary for universal quantum computation. We present a scheme…

Quantum Physics · Physics 2009-11-07 Xingxiang Zhou , Zheng-Wei Zhou , Guang-Can Guo , Marc J. Feldman

We study when a multipartite non--local unitary operation can deterministically or probabilistically simulate another one when local operations of a certain kind -in some cases including also classical communication- are allowed. In the…

Quantum Physics · Physics 2007-05-23 W. Dür , J. I. Cirac

We study the optimal quantum control of heteronuclear two-qubit systems described by a Hamiltonian containing both nonlocal internal drift and local control terms. We derive an explicit formula to compute the minimum time required to steer…

Quantum Physics · Physics 2013-11-07 Bin Li , Zu-Huan Yu , Shao-Ming Fei , XianQing Li-Jost

We consider the CNOT quantum gate as a physical action, i.e. as unitary in time evolution of the two-qubit system. This points to the modeling of the interaction Hamiltonian of the two-qubit system which would correspond to the CNOT…

Quantum Physics · Physics 2007-05-23 Miroljub Dugic

In this paper we study the properties of two-qubit gates. We review the most common parameterizations for the local equivalence classes of two-qubit gates and the connections between them. We then introduce a new discrete local invariant,…

Quantum Physics · Physics 2007-05-23 Laura Koponen , Ville Bergholm , Martti M. Salomaa

We theoretically study specific schemes for performing a fundamental two-qubit quantum gate via controlled atomic collisions by switching microscopic potentials. In particular we calculate the fidelity of a gate operation for a…

Quantum Physics · Physics 2009-10-31 T. Calarco , E. A. Hinds , D. Jaksch , J. Schmiedmayer , J. I. Cirac , P. Zoller

A quantitative description of the exchange interaction in quantum dots is relevant for modeling gate operations of spin qubits. By measuring the amplitude and frequency of exchange-driven qubit state oscillations, we measure the detuning…

We propose a method to implement a kind of non-local operations between spatially separated two systems with arbitrary high-dimensions by using only low-dimensional qubit quantum channels and classical bit communications. The result may be…

Quantum Physics · Physics 2007-05-23 Hao-Sheng Zeng , Yong-Guang Shan , Jian-Jun Nie , Le-Man Kuang

This paper addresses the problem of finding the depth overhead that will be incurred when running quantum circuits on near-term quantum computers. Specifically, it is envisaged that near-term quantum computers will have low qubit…

Quantum Physics · Physics 2020-07-29 Steven Herbert

Non-local quantum computation (NLQC) replaces a local interaction between two systems with a single round of communication and shared entanglement. Despite many partial results, it is known that a characterization of entanglement cost in at…

Quantum Physics · Physics 2025-06-02 Andreas Bluhm , Simon Höfer , Alex May , Mikka Stasiuk , Philip Verduyn Lunel , Henry Yuen

Instantaneous two-party quantum computation is a computation process with bipartite input and output, in which there are initial shared entanglement, and the nonlocal interactions are limited to simultaneous classical communication in both…

Quantum Physics · Physics 2023-06-23 Li Yu , Jie Xu , Fuqun Wang , Chui-Ping Yang

We prove that there is a trade-off relation between the entanglement cost and the number of rounds of communication, for two distant parties to accomplish a bidirectional quantum information task by local operations and classical…

Quantum Physics · Physics 2018-10-30 Eyuri Wakakuwa , Akihito Soeda , Mio Murao

We analytically determine the minimal time and the optimal control laws required for the realization, up to an assigned fidelity and with a fixed energy available, of entangling quantum gates ($\mathrm{CNOT}$) between indirectly coupled…

Quantum Physics · Physics 2014-12-01 A. Carlini , T. Koike

The impact of Coulomb interaction on the electronic properties of a quantum spin-Hall insulator is studied using quantum cluster methods, disentangling local from non-local effects. We identify different regimes, according to the value of…

Strongly Correlated Electrons · Physics 2021-12-22 Lorenzo Crippa , Adriano Amaricci , Severino Adler , Giorgio Sangiovanni , Massimo Capone

The information obtained from the operation of a quantum gate on only two complementary sets of input states is sufficient to estimate the quantum process fidelity of the gate. In the case of entangling gates, these conditions can be used…

Quantum Physics · Physics 2017-08-23 Holger F. Hofmann , Ryo Okamoto , Shigeki Takeuchi