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We propose a modular quantum computation architecture based on utilizing multipartite entanglement. Each module consists of a small-scale quantum computer comprising data, memory and entangling qubits. Entangling qubits are used to…

Quantum Physics · Physics 2024-12-16 Ferran Riera-Sàbat , Wolfgang Dür

Scalable quantum information processing will require quantum networks of qubits with the ability to coherently transfer quantum states between the desired sender and receiver nodes. Here we propose a scheme to implement a quantum router…

Quantum Physics · Physics 2020-01-08 K. S. Christensen , S. E. Rasmussen , D. Petrosyan , N. T. Zinner

Entanglement is a fundamental property of quantum mechanics, and is a primary resource in quantum information systems. Its manipulation remains a central challenge in the development of quantum technology. In this work, we demonstrate a…

Towards the full-fledged quantum computing, what do we need? Obviously, the first thing we need is a (many-body) quantum system, which is reasonably isolated from its environment in order to reduce the unwanted effect of noise, and the…

Quantum Physics · Physics 2017-01-03 Koji Maruyama , Daniel Burgarth

A seminal task in quantum information theory is to realize a device able to produce copies of a generic input state with the highest possible output fidelity, thus realizing an \textit{optimal} quantum cloning machine. Recently, the concept…

Entanglement is an important evidence that a quantum device can potentially solve problems intractable for classical computers. In this paper, we prepare connected graph states involving 8 to 16 qubits on ibmqx5, a 16-qubit superconducting…

Quantum Physics · Physics 2018-10-01 Yuanhao Wang , Ying Li , Zhang-qi Yin , Bei Zeng

Ising interaction between qubits could produce distortion in entangled pairs generated for engineering purposes (as in quantum computation) in presence of parasite magnetic fields, destroying or altering the expected behavior of process in…

Quantum Physics · Physics 2013-05-29 Francisco Delgado

The ability to realize high-fidelity quantum communication is one of the many facets required to build generic quantum computing devices. In addition to quantum processing, sensing, and storage, transferring the resulting quantum states…

We demonstrate high fidelity entangling quantum gates within a chain of five trapped ion qubits by optimally shaping optical fields that couple to multiple collective modes of motion. We individually address qubits with segmented optical…

Quantum Physics · Physics 2014-05-20 T. Choi , S. Debnath , T. A. Manning , C. Figgatt , Z. -X. Gong , L. -M. Duan , C. Monroe

We describe a quantum information processor (quantum computer) based on the hyperfine interactions between the conduction electrons and nuclear spins embedded in a two-dimensional electron system in the quantum-Hall regime. Nuclear spins…

Quantum Physics · Physics 2014-11-18 V. Privman , I. D. Vagner , G. Kventsel

We present Quantum Cloning Machines (QCM) that transform N identical qubits into $M>N$ identical copies and we prove that the fidelity (quality) of these copies is optimal. The connection between cloning and measurement is discussed in…

Quantum Physics · Physics 2009-01-23 N. Gisin , S. Massar

A major question for condensed matter physics is whether a solid-state quantum computer can ever be built. Here we discuss two different schemes for quantum information processing using semiconductor nanostructures. First, we show how…

Quantum Physics · Physics 2016-09-08 John H. Reina , Luis Quiroga , Neil F. Johnson

The engineering of quantum devices has reached the stage where we now have small scale quantum processors containing multiple interacting qubits within them. Simple quantum circuits have been demonstrated and scaling up to larger numbers is…

he multiqubit entangled states are coherently controlled in the quantum spin systems composed of $N+1$ interacting antiferromagnetic molecular rings. The tunable intermolecular couplings arise from the local exchange interactions between…

Quantum Physics · Physics 2009-03-17 Xiang Hao , Tao Pan , Taocheng Zang , Shiqun Zhu

We discuss quantum information processing machines. We start with single purpose machines that either redistribute quantum information or identify quantum states. We then move on to machines that can perform a number of functions, with the…

Quantum Physics · Physics 2015-05-13 Mark Hillery , Vladimir Buzek

We describe a qubit encoded in continuous quantum variables of an rf superconducting quantum interference device. Since the number of accessible states in the system is infinite, we may protect its two-dimensional subspace from small errors…

Mesoscale and Nanoscale Physics · Physics 2007-08-02 Mateusz Cholascinski , Yuriy Makhlin , Gerd Schön

The N to M (M>N) universal quantum broadcasting of mixed states are proposed for qubits system. The broadcasting of mixed states is universal and optimal in the sense that the shrinking factor is independent of input state and achieves the…

Quantum Physics · Physics 2009-11-13 Gui-Fang Dang , Heng Fan

A completely depolarising quantum channel always outputs a fully mixed state and thus cannot transmit any information. In a recent Letter [D. Ebler et al., Phys. Rev. Lett. 120, 120502 (2018)], it was however shown that if a quantum state…

Quantum Physics · Physics 2020-09-25 Alastair A. Abbott , Julian Wechs , Dominic Horsman , Mehdi Mhalla , Cyril Branciard

A conception of virtual quantum information bit - virtual qubit - is introduced. It is shown by means of virtual qubit representation that four states of a single quantum particle is enough for implementation of full set of the gates, which…

Quantum Physics · Physics 2015-06-26 Alexander R. Kessel , Vladimir L. Ermakov

Quantum networks are a keystone of the quantum internet. However, existing implementations remain largely confined to static point-to-point links due to the absence of a switching paradigm capable of dynamically routing fragile quantum…