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Related papers: A near deterministic linear optical CNOT gate

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We present the first quantum controlled-NOT (CNOT) gate realized using a fiber-based indistinguishable photon-pair source in the 1.55 $\mu$m telecommunications band. Using this free-space CNOT gate, all four Bell states are produced and…

Entangling gates between qubits are a crucial component for performing algorithms in quantum computers. However, any quantum algorithm must ultimately operate on error-protected logical qubits encoded in high-dimensional systems. Typically,…

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

We show that it is possible to reduce the number of two-qubit gates needed for the construction of an arbitrary controlled-unitary transformation by up to two times using a tunable controlled-phase gate. On the platform of linear optics,…

Quantum Physics · Physics 2015-04-22 Karel Lemr , Karol Bartkiewicz , Antonín Černoch , Miloslav Dušek , Jan Soubusta

We suggest an efficient scheme for quantum computation with linear optical elements utilizing "linked" photon states. The linked states are designed according to the particular quantum circuit one wishes to process. Once a linked-state has…

Quantum Physics · Physics 2009-11-10 Nadav Yoran , Benni Reznik

One of the main problems that optical quantum computing has to overcome is the efficient construction of two-photon gates. Theoretically these gates can be realized using Kerr-nonlinearities, but the techniques involved are experimentally…

Quantum Physics · Physics 2016-07-15 Pål Sundsøy , Egil Fjeldberg

A strong limitation of linear optical quantum computing is the probabilistic operation of two-quantum bit gates based on the coalescence of indistinguishable photons. A route to deterministic operation is to exploit the single-photon…

Based on electron spins in semiconductor quantum dots as qubits, a new quantum controlled-NOT(CNOT) gate is constructed in solid nanostructure without resorting to spin-spin interactions. Single electron tunneling technology and coherent…

Quantum Physics · Physics 2009-11-13 Yin-Zhong Wu , Wei-Min Zhang

We investigate the computational power of passive and active linear optical elements and photo-detectors. We show that single photon sources, passive linear optics and photo-detectors are sufficient for implementing reliable quantum…

Quantum Physics · Physics 2007-05-23 E. Knill , R. Laflamme , G. Milburn

Photon modes of reverse rotation in ring QED-cavity coupled with single atom are considered. By applying Schrieffer-Wolf transformation for the off-resonant light-atom interaction, an effective Hamiltonian of the evolution of the photon…

Single photons provide excellent quantum information carriers, but current schemes for preparing, processing and measuring them are inefficient. For example, down-conversion provides heralded, but randomly timed single photons, while…

Quantum Physics · Physics 2012-02-07 N. K. Langford , S. Ramelow , R. Prevedel , W. J. Munro , G. J. Milburn , A. Zeilinger

We propose a scheme for the construction of a CNOT gate by adiabatic passage in an optical cavity. In opposition to a previously proposed method, the technique is not based on fractional adiabatic passage, which requires the control of the…

Quantum Physics · Physics 2009-11-11 N. Sangouard , X. Lacour , S. Guerin , H. R. Jauslin

We design a controlled-phase gate for linear optical quantum computing by using photodetectors that cannot resolve photon number. An intrinsic error-correction circuit corrects errors introduced by the detectors. Our controlled-phase gate…

Quantum Physics · Physics 2009-09-29 Mark M. Wilde , Federico Spedalieri , Jonathan P. Dowling , Hwang Lee

It is well known that a parallel quantum computer is more powerful than a classical one. So far, there are some important works about the construction of universal quantum logic gates, the key elements in quantum computation. However, they…

Quantum Physics · Physics 2014-05-02 Bao-Cang Ren , Fu-Guo Deng

Based on our recent paper [arXiv:2206.12176 (2022)], we propose a scalable heteronuclear architecture of parallel implementation of CNOT gates in arrays of alkali-metal neutral atoms for quantum information processing. We considered a…

Quantum Physics · Physics 2023-10-02 Ahmed M. Farouk , I. I. Beterov , Peng Xu , I. I. Ryabtsev

Single-photon detection is an essential component in many experiments in quantum optics, but remains challenging in the microwave domain. We realize a quantum non-demolition detector for propagating microwave photons and characterize its…

Photonic quantum computing has recently emerged as a promising candidate for fault-tolerant quantum computing by photonic qubits. These protocols make use of nondeterministic gates, enabling universal quantum computation. However, the…

Quantum Physics · Physics 2024-07-11 Csaba Czabán , Zoltán Kolarovszki , Márton Karácsony , Zoltán Zimborás

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

Photonics is a promising architecture for the realisation of quantum information processing, since the two-photon interaction, or non-linearity, necessary to build logical gates can efficiently be realised by the use of interference with…

Quantum Physics · Physics 2011-12-06 Thomas Jennewein , Marco Barbieri , Andrew G. White

We show that the optical Kerr effect can be used to construct a quantum phase gate. It is well known from quantum nondemolition techniques that, as two photon field modes pass through a Kerr medium, the phase of each mode will be shifted,…

Quantum Physics · Physics 2007-05-23 S. Glancy , J. M. LoSecco , C. E. Tanner