Implementations of more general solid-state (SWAP) 1 / m and controlled-(swap) 1 / m gates

Abstract

Universal quantum gates are the core elements in quantum information processing. We design two schemes to realize more general (SWAP) 1/m and controlled-(swap) 1/m gates (for integer m 1  ) by directing flying single photons to solid-state quantum dots. The parameter m is easily controlled by adjusting two quarter-wave plates and one half-wave plate. Additional computational qubits are not required to construct the two gates. Evaluations of the gates indicate that our proposals are feasible with current experimental technology.

Demonstration of deterministic SWAP gate between superconducting and frequency-encoded microwave-photon qubits

“…This is a quite common element in a superconducting quantum processor adopting the dispersive qubit readout [38,39]. Gate tunability-although we demonstrate only the SWAP gate in this work, the present gate is a more general (SWAP) α gate (0 ≤ α ≤ 1) [40][41][42][43] equipped with an in situ tunability of the gate type α through the amplitude and frequency of the drive pulse to the atom [29]. In particular, in combination with the atom-photon entangling gate ( √ SWAP, α = 1/2), the present scheme is applicable to the entanglement generation between remote superconducting qubits as well as the deterministic photon-photon entangling gate.…”

Complete Hyperentangled Bell States Analysis For Polarization‐Spatial‐Time‐Bin Degrees of Freedom with Unity Fidelity

“…Such two schemes were further improved to the error-detected ones by Wang et al, [57] Zheng et al, [58] and Cao et al [59] QDs, named as artificial atom, have been recognized as the promising candidates for QIP. [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] Nowadays, schemes for implementing quantum gates have been proposed in hybrid photon-QD systems, [63][64][65] solid-QD systems, [66,67] and flying photon systems, [68,69] respectively. Quantum entanglements between a QD spin and a single photon [70] and between two distance QD hole spins [71] have been experimentally demonstrated.…”

Complete hyperentangled Bell states analysis for polarization-spatial-time-bin degrees of freedom with unity fidelity

“…Such two schemes were further improved to the error-detected ones by Wang et al, [57] Zheng et al, [58] and Cao et al [59] QDs, named as artificial atom, have been recognized as the promising candidates for QIP. [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] Nowadays, schemes for implementing quantum gates have been proposed in hybrid photon-QD systems, [63][64][65] solid-QD systems, [66,67] and flying photon systems, [68,69] respectively. Quantum entanglements between a QD spin and a single photon [70] and between two distance QD hole spins [71] have been experimentally demonstrated.…”