Universal hybrid three-qubit quantum gates assisted by a nitrogen-vacancy center coupled with a whispering-gallery-mode microresonator

Abstract

We investigate the construction of two universal three-qubit quantum gates in a hybrid system. The designed system consists of a flying photon and a stationary negatively charged nitrogen-vacancy (NV) center fixed on the periphery of a whispering-gallery-mode (WGM) microresonator, with the WGM cavity coupled to tapered fibers functioning as an add-drop structure. These gate operations are accomplished by encoding the information both on the spin degree of freedom of the electron confined in the NV center and on the polarization and spatial-mode states of the flying photon, respectively. Compared with previous schemes, our proposed scheme leads to a reduction of time and resource consumption in the processing. Moreover, these gates work in a deterministic way with no extra qubits required, which is feasible with current technologies. Both proposed gate operations could be physically implemented in one step, which provides a promising approach for quantum information processing ranging from distributed quantum computation to long-distance quantum communication.

Hyper-parallel Toffoli gate on three-photon system with two degrees of freedom assisted by single-sided optical microcavities

“…Some schemes for optical hyper-CNOT gates assisted by QDs or NV centres have been proposed by Ren et al [25][26][27]. Wang et al [28,29] designed some quantum circuits for hyper-parallel universal quantum gates acting on hybrid photon-matter systems.…”

“…By the first approach, the quantum circuits for solid-state electronic CNOT gate [23] and flying photonic Toffoli gate [24] have been designed. By the second approach, schemes for implementing hyper-parallel photon-based CNOT gate [25][26][27] and hyperparallel photon-matter-based universal gates [28,29] have been proposed. The hyperentangledcluster-state-based quantum computing have been demonstrated in recent years [30].…”

Universal photonic quantum gates assisted by ancilla diamond nitrogen-vacancy centers coupled to resonators

“…The general resonators employed in our proposals should be polarization-degenerate ones, and they can be achieved by employing silica microtoroid resonators [64,71,76,77] fabricated on silicon wafers, H1 planar photonic crystal cavities [78][79][80][81] formed in thin semiconductor slab waveguides, micropillar cavities [82][83][84] grown by molecular-beam epitaxy on GaAs [100] substrates, or fiber-based Fabry-Perot cavities [72][73][74]. The degeneracy of the two orthogonal polarization modes of the H1 cavity is broken by systematic errors, such as hole shape and period, in the imperfect fabrication process.…”

Realization of quantum gates based on three-dimensional harmonic oscillator in a time-varying electromagnetic field

“…Using time-dependent second-order perturbation theory applied to this perturbed oscillator, we compute the unitary evolution operator up to O(e 2 ). This approximate unitary evolution operator at time T is expressible as a linear plus a quadratic function of the electromagnetic field (E(t), B(t), 0 ≤ t ≤ T ), and hence, we are able to compute up to O(e 2 ), the error energy between this approximate unitary gate and a given unitary gate [3][4][5][6][7][8][9][10][11]. This error energy is now a linear-quadratic function of the electromagnetic field (E(t), B(t), 0 ≤ t ≤ T ).…”