Loss-resistant state teleportation and entanglement swapping using a quantum-dot spin in an optical microcavity

TL;DR

This paper proposes a loss-resistant quantum teleportation and entanglement swapping scheme using a quantum-dot spin in an optical microcavity, capable of high efficiency and fidelity with current technology.

Contribution

It introduces a novel Bell-state analyzer with built-in spin memory for loss-resistant quantum communication using quantum dots.

Findings

Achieves high fidelity in both weak and strong coupling regimes

Feasible with current quantum dot and microcavity technology

Proposes a spin manipulation method to preserve coherence

Abstract

We present a scheme for efficient state teleportation and entanglement swapping using a single quantum-dot spin in an optical microcavity based on giant circular birefringence. State teleportation or entanglement swapping is heralded by the sequential detection of two photons, and is finished after the spin measurement. The spin-cavity unit works as a complete Bell-state analyzer with a built-in spin memory allowing loss-resistant repeater operation. This device can work in both the weak coupling and the strong coupling regime, but high efficiencies and high fidelities are only achievable when the side leakage and cavity loss is low. We assess the feasibility of this device, and show it can be implemented with current technology. We also propose a spin manipulation method using single photons, which could be used to preserve the spin coherence via spin echo techniques.