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Related papers: An All Optical Fibre Quantum Controlled-NOT Gate

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We describe the operation and tolerances of a non-deterministic, coincidence basis, quantum CNOT gate for photonic qubits. It is constructed solely from linear optical elements and requires only a two-photon source for its demonstration.

Quantum Physics · Physics 2009-11-07 T. C. Ralph , N. K. Langford , T. B. Bell , A. G. White

As primitives for entanglement generation, controlled phase gates take a central role in quantum computing. Especially in ideas realizing instances of quantum computation in linear optical gate arrays a closer look can be rewarding. In such…

Quantum Physics · Physics 2015-05-14 K. Kieling , J. L. O'Brien , J. Eisert

We study the realization of a Toffoli gate with superconducting qubits in a circuit-QED setup using quantum-control methods. Starting with optimized piecewise-constant control fields acting on all qubits and typical strengths of XY-type…

Quantum Physics · Physics 2012-02-14 Vladimir M. Stojanovic , A. Fedorov , A. Wallraff , C. Bruder

Quantum Fourier transform (QFT) is a key function to realize quantum computers. A QFT followed by measurement was demonstrated on a simple circuit based on fiber-optics. The QFT was shown to be robust against imperfections in the rotation…

Quantum Physics · Physics 2007-05-23 Akihisa Tomita , Kazuo Nakamura

Integrated photonic circuits have a strong potential to perform quantum information processing. Indeed, the ability to manipulate quantum states of light by integrated devices may open new perspectives both for fundamental tests of quantum…

The two-qubit controlled-not (C-NOT) gate is an essential component for gate-based quantum circuits. In fact, its operation, combined with single qubit rotations allows to realise any quantum circuit. Several strategies have been adopted in…

Quantum Physics · Physics 2026-04-28 Federico Pegoraro , Philip Held , Jonas Lammers , Benjamin Brecht , Christine Silberhorn

We demonstrate laser-driven two-qubit and single-qubit logic gates with fidelities 99.9(1)% and 99.9934(3)% respectively, significantly above the approximately 99% minimum threshold level required for fault-tolerant quantum computation,…

Quantum Physics · Physics 2016-08-08 C. J. Ballance , T. P. Harty , N. M. Linke , M. A. Sepiol , D. M. Lucas

Implementation of quantum logic gates with linear optical elements plays a prominent role in quantum computing due to the relatively easier manipulation and realization. We present efficient schemes to implement controlled-NOT (CNOT) gate…

Quantum Physics · Physics 2026-02-11 Gui-Long Jiang , Jun-Bin Yuan , Wen-Qiang Liu , Hai-Rui Wei

Inevitable interactions with the reservoir largely degrade the performance of non-local gates, which hinders practical quantum computation from coming into existence. Here we experimentally demonstrate a 99.920(7)\%-fidelity controlled-NOT…

Quantum Physics · Physics 2022-12-07 Tianyu Xie , Zhiyuan Zhao , Shaoyi Xu , Xi Kong , Zhiping Yang , Mengqi Wang , Ya Wang , Fazhan Shi , Jiangfeng Du

A new modified version of the Oxford purification protocol is proposed. This version is based on the controlled-controlled NOT gate instead of controlled NOT in the original one. Comparisons between the results of the new version and the…

Quantum Physics · Physics 2009-11-13 Nasser Metwally , Abdel-Shafy F. Obada

A single-shot Toffoli, or controlled-controlled-NOT, gate is desirable for classical and quantum information processing. The Toffoli gate alone is universal for reversible computing and, accompanied by the Hadamard gate, forms a universal…

Quantum Physics · Physics 2015-05-21 Ehsan Zahedinejad , Joydip Ghosh , Barry C. Sanders

A distributed network architecture in which flying photons connect individual modules containing stationary atomic qubits is a promising approach for scaling up neutral-atom based quantum-computing platforms. We consider an all-fiber based…

Quantum Physics · Physics 2026-02-02 Tim Keller , Seigo Kikura , Rui Asaoka , Yasunari Suzuki , Yuuki Tokunaga , Takao Aoki

We present a method to enact a deterministic, measurement-free, optically generated controlled-phase gate on two qubits defined by single electrons trapped in large-area quantum dots in a planar microcavity. This method is robust to optical…

Quantum Physics · Physics 2009-10-28 T. D. Ladd , Y. Yamamoto

Scaling up linear-optics quantum computing will require multi-photon gates which are compact, phase-stable, exhibit excellent quantum interference, and have success heralded by the detection of ancillary photons. We investigate…

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

High-dimensional quantum systems have been used to reveal interesting fundamental physics and to improve information capacity and noise resilience in quantum information processing. However, it remains a significant challenge to realize…

Quantum Physics · Physics 2024-04-24 Mingyuan Chen , Jiangshan Tang , Miao Cai , Franco Nori , Keyu Xia

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

In principle the Zeno effect controlled-sign gate of Franson et al's (PRA 70, 062302, 2004) is a deterministic two-qubit optical gate. However, when realistic values of photon loss are considered its fidelity is significantly reduced. Here…

Quantum Physics · Physics 2009-11-13 Patrick M. Leung , Timothy C. Ralph

Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental…

We demonstrate high fidelity single-qubit gate operation in a trapped single neutral atom. The atom is trapped in the recently invented magic-intensity optical dipole trap (MI-ODT) with more stable magnetic field. The MI-ODT efficiently…

Quantum Physics · Physics 2018-12-19 Cheng Sheng , Xiaodong He , Ruijun Guo , Kunpeng Wang , Peng Xu , Zongyuan Xiong , Min Liu , Jin Wang , Mingsheng Zhan