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Related papers: Linear Optical CNOT Gate in the Coincidence Basis

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We demonstrate the possibility to perform distributed quantum computing using only single photon sources (atom-cavity-like systems), linear optics and photon detectors. The qubits are encoded in stable ground states of the sources. To…

Quantum Physics · Physics 2009-11-10 Yuan Liang Lim , Almut Beige , Leong Chuan Kwek

We present photonic quantum computing architectures that can deal with both probabilistic (heralded) generation of single photons and probabilistic gates without making use of coherent switching. The only required dynamical element is the…

Quantum Physics · Physics 2023-03-08 Terry Rudolph

Photonic quantum computing offers a promising platform for quantum information processing, benefiting from the long coherence times of photons and their ease of manipulation. This paper presents a scheme for implementing a deterministic…

Quantum Physics · Physics 2025-04-22 Evangelos Varvelis , Joachim Ankerhold

Accurate characterisation of two-qubit gates will be critical for any realisation of quantum computation. We discuss a range of measurements aimed at characterising a two-qubit gate, specifically the CNOT gate. These measurements are…

Integrated photonic circuits are a promising platform for scalable quantum information processing, but their performance is often constrained by component sensitivity to fabrication imperfections. Directional couplers, which are crucial…

Scalable quantum computation with linear optics was considered to be impossible due to the lack of efficient two-qubit logic gates, despite its ease of implementation of one-qubit gates. Two-qubit gates necessarily need a nonlinear…

Quantum Physics · Physics 2007-05-23 Jonathan P. Dowling , James D. Franson , Hwang Lee , Gerald J. Milburn

Much of the anticipation accompanying the development of a quantum computer relates to its application to simulating dynamics of another quantum system of interest. Here we study the building blocks for simulating quantum spin systems with…

Quantum computers require technologies that offer both sufficient control over coherent quantum phenomena and minimal spurious interactions with the environment. We show, that photons confined to photonic crystals, and in particular to…

Quantum Physics · Physics 2009-11-10 Dimitris G. Angelakis , Marcelo Franca Santos , Vassilis Yannopapas , Artur Ekert

We propose an implementation of a CNOT quantum gate for quantum computing based on a patterned microcavity polariton system, which can be manufactured using the modern technological facilities. The qubits are encoded in the spin of…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 D. D. Solnyshkov , O. Bleu , G. Malpuech

Proposed configurations for the implementation of graphene-based CNOT and Toffoli gates working at room temperature are presented. These two logic gates, essential for any quantum computing algorithm, involve ballistic Y junctions for qubit…

Mesoscale and Nanoscale Physics · Physics 2014-12-02 Daniela Dragoman , Mircea Dragoman

In this paper, with the weak cross-Kerr nonlinearity, we first present a special experimental scheme called C-path gate with which the realization of all possible bipartite POVMs of two-photon polarization states can be simpler and nearly…

Quantum Physics · Physics 2009-02-26 Qing Lin , Jian Li

This work proposes numerical tests which determine whether a two-qubit operator has an atypically simple quantum circuit. Specifically, we describe formulae, written in terms of matrix coefficients, characterizing operators implementable…

Quantum Physics · Physics 2009-11-10 Vivek V. Shende , Stephen S. Bullock , Igor L. Markov

Optimal construction of quantum operations is a fundamental problem in the realization of quantum computation. We here introduce a newly discovered quantum gate, B, that can implement any arbitrary two-qubit quantum operation with minimal…

Quantum Physics · Physics 2009-11-10 Jun Zhang , Jiri Vala , Shankar Sastry , K. Birgitta Whaley

Numerical optimization is used to design linear-optical devices that implement a desired quantum gate with perfect fidelity, while maximizing the success rate. For the 2-qubit CS (or CNOT) gate, we provide numerical evidence that the…

Quantum Physics · Physics 2015-05-13 Dmitry B. Uskov , Lev Kaplan , A. Matthew Smith , Sean D. Huver , Jonathan P. Dowling

We introduce unitary quantum gates for photon pair creation in spontaneous parametric down-conversion nonlinear crystals (NLs) and for photon path alignment. These are the two key ingredients for the method of "induced coherence without…

Quantum Physics · Physics 2017-10-16 Sahar Alipour , Mario Krenn , Anton Zeilinger

We examine the realization of a quantum CNOT gate by adiabatic operations.The principles of such systems and their analysis are briefly discussed and a model consisting of two weakly coupled double- potential well qubits is studied…

Condensed Matter · Physics 2009-11-07 V. Corato , P. Silvestrini , L. Stodolsky , J. Wosiek

Linear optics quantum logic gates are the best tool to generate multi-photon entanglement. Simplifying a recent approach [Phys. Rev. A 65, 062324; Phys. Rev. A 66, 024308] we were able to implement the conditional phase gate with only one…

Quantum Physics · Physics 2009-11-11 Nikolai Kiesel , Christian Schmid , Ulrich Weber , Rupert Ursin , Harald Weinfurter

Quantum interrogation can be used as a basic resource for quantum information. This paper presents its applications to entanglement creation and to optical quantum computation. The starting point will be a photon to particle quantum…

Quantum Physics · Physics 2009-01-30 Juan Carlos Garcia-Escartin , Pedro Chamorro-Posada

We provide a method for compiling approximate multi-controlled single qubit gates into quantum circuits without ancilla qubits. The total number of elementary gates to decompose an n-qubit multi-controlled gate is proportional to 32n, and…

One of the main advantages of an optical approach to quantum computing is the fact that optical fibers can be used to connect the logic and memory devices to form useful circuits, in analogy with the wires of a conventional computer. Here…

Quantum Physics · Physics 2016-09-08 T. B. Pittman , B. C Jacobs , J. D. Franson