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Related papers: Linear optical Fredkin gate based on partial-SWAP …

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We present two efficient methods for implementing the Fredkin gate with atoms separately trapped in an array of three high-$Q$ coupled cavities. The first proposal is based on the resonant dynamics, which leads to a fast resonant…

Quantum Physics · Physics 2015-06-17 Xiao-Qiang Shao , Tai-Yu Zheng , Xun-Li Feng , C. H. Oh , Shou Zhang

We present a linear-optical scheme for a controlled-phase gate with tunable phase shift programmed by a qubit state. In contrast to all previous tunable controlled-phase gates, the phase shift is not hard-coded into the optical setup, but…

Quantum Physics · Physics 2015-10-28 Karel Lemr , Karol Bartkiewicz , Antonín Černoch

An analogy between the twisted quantum xxz model and a gated Josephson junction array is used to predict sharp structure in the critical currents versus gate voltage, and fractional AC Josephson frequencies. We prove selection rules for…

Superconductivity · Physics 2009-10-31 Ehud Altman , Assa Auerbach

A particular type of linear optical multiport, the Grover four-port, has previously been shown to couple the spatial symmetry of a photon to its direction of travel. It is shown here that use of a nonstandard choice of qubit, based on…

We demonstrate a new architecture for an optical entangling gate that is significantly simpler than previous realisations, using partially-polarising beamsplitters so that only a single optical mode-matching condition is required. We…

We present a systematic comparison of different methods of fidelity estimation of a linear optical quantum controlled-Z gate implemented by two-photon interference on a partially polarizing beam splitter. We have utilized a linear fidelity…

Quantum Physics · Physics 2015-06-19 M. Micuda , M. Sedlak , I. Straka , M. Mikova , M. Dusek , M. Jezek , J. Fiurasek

Recently it was realized that linear optics and photo-detectors with feedback can be used for theoretically efficient quantum information processing. The first of three steps toward efficient linear optics quantum computation (eLOQC) was to…

Quantum Physics · Physics 2013-05-29 E. Knill

Knill, Laflamme, and Milburn [Nature 409, 46 (2001)] showed that linear optics techniques could be used to implement a nonlinear sign gate. They also showed that two of their nonlinear sign gates could be combined to implement a…

Quantum Physics · Physics 2021-03-08 S. U. Shringarpure , J. D. Franson

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 gates are the essential block for quantum computer. High-dimensional quantum gates exhibit remarkable advantages over their two-dimensional counterparts for some quantum information processing tasks. Here we present a family of…

Quantum Physics · Physics 2026-02-10 Huan-Chao Gao , Guo-Zhu Song , Hai-Rui Wei

Integrating a single Fredkin (controlled swap) gate to the previously introduced W state fusion mechanism (Ozdemir et al, N. J. Phys. 13, 103003, 2011) and using an ancillary photon, we increase the size of the fused W states and…

Quantum Physics · Physics 2014-02-14 Sinan Bugu , Can Yesilyurt , Fatih Ozaydin

We propose and experimentally demonstrate a scheme for implementation of a maximally entangling quantum controlled-Z gate between two weakly interacting systems. We conditionally enhance the interqubit coupling by quantum interference. Both…

Quantum Physics · Physics 2015-09-23 M. Micuda , R. Starek , I. Straka , M. Mikova , M. Dusek , M. Jezek , R. Filip , J. Fiurasek

We investigate the feasibility of single-shot Toffoli- and Fredkin-gate realizations in qubit arrays with Heisenberg-type exchange interactions between adjacent qubits. As follows from the Lie-algebraic criteria of controllability, such an…

Quantum Physics · Physics 2019-01-30 Vladimir M. Stojanovic

We discuss and experimentally demonstrate a probabilistic Hadamard gate for coherent state qubits. The scheme is based on linear optical components, non-classical resources and the joint projective action of a photon counter and a homodyne…

Quantum Physics · Physics 2015-03-19 Anders Tipsmark , Ruifang Dong , Amine Laghaout , Petr Marek , Miroslav Jezek , Ulrik L. Andersen

We introduce a nonunitary partial-swap gate for fusing arbitrary small-sized photonic W-states into a large-scale entangled network of W-state efficiently without ancillary photons. A partial-swap gate is designed in an optical architecture…

Quantum Physics · Physics 2020-11-24 Hai-Rui Wei , Wen-Qiang Liu , Leong-Chuan Kwek

Effective quantum information processing is tantamount in part to the minimization the quantum resources needed by quantum logic gates. Here, we propose an optimization of an n-controlled-qubit Fredkin gate with a maximum of 2n+1 two-qubit…

Quantum Physics · Physics 2020-12-01 Wen-Qiang Liu , Hai-Rui Wei , Leong-Chuan Kwek

We theoretically present a method to realize a deterministic photon-photon (SWAP)^{1/2} gate using a three-level lambda system interacting with single photons in reflection geometry. The lambda system is used completely passively as a…

Quantum Physics · Physics 2015-05-14 Kazuki Koshino , Satoshi Ishizaka , Yasunobu Nakamura

We experimentally demonstrate a programmable quantum gate that applies a sign flip operation to data qubit in an arbitrary basis fully specified by the quantum state of a two-qubit program register. Our linear-optical implementation is…

Quantum Physics · Physics 2009-05-26 Lukas Slodicka , Miroslav Jezek , Jaromir Fiurasek

In this paper, the problem of finding optimal success probabilities of static linear optics quantum gates is linked to the theory of convex optimization. It is shown that by exploiting this link, upper bounds for the success probability of…

Quantum Physics · Physics 2009-11-10 J. Eisert

Universal quantum gates lie at the heart of designing quantum computer. We construct two compact quantum circuits to implement post-selected controlled-phase-flip (CPF) gate and Toffoli gate with linear optics assisted by one and two single…

Quantum Physics · Physics 2022-11-18 Wen-Qiang Liu , Hai-Rui Wei