Three‐Photon Polarization‐Spatial Hyperparallel Quantum Fredkin Gate Assisted by Diamond Nitrogen Vacancy Center in Optical Cavity

Abstract

The construction of a near-deterministic photonic hyperparallel quantum Fredkin (hyper-Fredkin) gate is investigated for a three-photon system with the optical property of a diamond nitrogen vacancy center embedded in an optical cavity (cavity-NV center system). This hyper-Fredkin gate can be used to perform double Fredkin gate operations on both the polarization and spatial-mode degrees of freedom (DOFs) of a three-photon system with a near-unit success probability, compared with those on the double three-photon systems in one DOF. In this proposal, the hybrid quantum logic gate operations are the key elements of the hyper-Fredkin gate, and only two cavity-NV center systems are required. Moreover, the possibility of constructing a high-fidelity and high-efficiency hyper-Fredkin gate in the experimental environment of a cavity-NV center system is discussed, which may be used to implement high-fidelity photonic computational tasks in two DOFs with a high efficiency.and three-photon quantum entangling gates are essential elements for solving universal quantum computational tasks. [1][2][3][4][5][6][7][8][9][10] In the construction of photonic quantum entangling gates, the strong interaction between photons is an essential task to be overcome. By using linear optics, auxiliary photons, and photon detectors, the strong photonphoton interaction can be obtained, and many schemes have been proposed and demonstrated for photonic twoqubit [11][12][13] and three-qubit [14,15] quantum entangling gates in the past few years. In 2006, Fiurášek [14] proposed a threephoton Fredkin gate with the success probability 4.1 × 10 −3 by using linear optical elements, auxiliary entangled photon pairs, and the single-photon detectors. In 2008, Gong et al. [15] improved the success probability of three-photon Fredkin gate to 1/64 by using linear optical elements and the three-photon time entangled source.The near-deterministic photonic quantum entangling gates have been investigated with nonlinear optical elements, [16][17][18][19][20][21][22][23][24] such as the two-photon controlled-not (CNOT) gate with cross-Kerr nonlinearity [16] and two-photon controlled-phase-flip (CPF) gate with cavity quantum electrodynamics (QED). [17] The interaction between dipole-emitter and photon in cavity QED is very useful for obtaining strong interaction between photons. The electron-spins in quantum dot [25][26][27][28][29] and nitrogen vacancy (NV) center in diamond [30][31][32][33][34][35][36][37] are promising dipole-emitters for cavity QED. With the optical property of quantum dot (or NV center in diamond) embedded in optical cavity, the quantum entangling gates can be constructed for photon systems [19,20,27] and photonelectron-spin hybrid systems. [36,37] Considering the high-capacity property, the photon system can carry more quantum information by encoding the multiple degrees of freedom (DOFs) as qubits. In quantum communication, the entanglement can be prepared in the multiple DOFs of photon system, called hyperentanglement, [38] which can larg...

Optical Fredkin gate assisted by quantum dot within optical cavity under vacuum noise and sideband leakage

“…QD QD QD QD theoretical circuit of fredkin gate. First, we introduce the theoretical Fredkin (controlled-swap operation) gate [23][24][25][26] . In Fig.…”

“…Many researchers have proposed to directly design or realize multi-qubit controlled gates, such as Fredkin gate [23][24][25][26] , Toffoli gate 27,28 , and universal multi-qubit gates [29][30][31][32] . The Fredkin gate, which is a controlled-swap gate, can be widely applicable in various quantum information processing schemes (quantum communication [33][34][35][36] and quantum computation [37][38][39][40] ).…”

“…In quantum dot (QD)-cavity system, which consists of an injected excess electron and a confined negatively charged exciton (X − ) in optical cavity 2,4,[11][12][13]15,[41][42][43][44][45][46][47][48][49][50][51][52][53][54] , quantum information can be well stored for a long electron-spin coherence time (T 2 e~μ s) 43,45,46,[55][56][57] and a limited spin relaxation period (T 1 e~m s) 42,50,58,59 against the influence (decoherence effect) of environment. Therefore, several diverse quantum information processing schemes have been designed between photons and electrons in the QD-cavity system, as quantum controlled gates 21,[24][25][26]30,31,[47][48][49]52,60 , quantum communications [10][11][12][13]15,42…”

The Linear Optical Unambiguous Discrimination of Hyperentangled Bell States Assisted by Time Bin

“…[34] Hyperentanglement has important applications in quantum error-correcting, [35,36] quantum cryptography, [37,38] quantum repeater, [39] and entanglement purification. [52][53][54][55] In high-capacity quantum communication, hyperentangled Bell-state analysis (HBSA) is one of the most popular components to read out the quantum information. [52][53][54][55] In high-capacity quantum communication, hyperentangled Bell-state analysis (HBSA) is one of the most popular components to read out the quantum information.…”

High‐Fidelity Hybrid Quantum Gates between a Flying Photon and Diamond Nitrogen‐Vacancy Centers Assisted by Low‐Q Single‐Sided Cavities

“…Over the past decades, many physical systems have been researched for quantum computation, such as ion traps, nuclear magnetic resonance (NMR), quantum dots (QDs), superconducting circuits, diamond nitrogen‐vacancy (NV) centers, photons with one degree of freedom (DOF) or with multiple DOFs, and hybrid systems . Among these systems, the hybrid system composed of a flying photon and a few NV centers is considered a very attractive candidate.…”