Deterministic CNOT gate and entanglement swapping for photonic qubits using a quantum-dot spin in a double-sided optical microcavity

TL;DR

This paper presents a deterministic, scalable scheme for implementing a CNOT gate and entanglement swapping between photonic qubits using a quantum-dot spin in a double-sided microcavity, applicable in various coupling regimes.

Contribution

It introduces a nondestructive, heralded method for quantum gate operations and entanglement swapping with quantum-dot spins in microcavities, advancing photonic quantum communication.

Findings

Scheme works in weak and strong coupling regimes

Achieves nondestructive and heralded quantum operations

Enables long-distance quantum communication

Abstract

We propose a deterministic and scalable scheme to construct a two-qubit controlled-NOT (CNOT) gate and realize entanglement swapping between photonic qubits using a quantum-dot (QD) spin in a double-sided optical microcavity. The scheme is based on spin selective photon reflection from the cavity and can be achieved in a nondestructive and heralded way. We assess the feasibility of the scheme and show that the scheme can work in both the weak coupling and the strong coupling regimes. The scheme opens promising perspectives for long-distance photonic quantum communication and distributed quantum information processing.