Entanglement of remote material qubits through nonexciting interaction with single photons

TL;DR

This paper presents a novel scheme for entangling remote material qubits using single photons through non-exciting interactions, enabling scalable, high-fidelity entanglement with realistic experimental parameters.

Contribution

The scheme introduces a non-exciting, state-dependent reflection/transmission method for entangling multiple qubits, scalable and robust against imperfections, demonstrated with optical cavity systems.

Findings

Achieves over 0.99 fidelity with just two photons.

Scalable to multiple qubits without changing qubit states.

Compatible with current experimental setups.

Abstract

We propose a scheme to entangle multiple material qubits through interaction with single photons via non-exciting processes associated with strongly coupling systems. The basic idea is based on the material state dependent reflection and transmission for the input photons. Thus, the material qubits in several systems can be entangled when one photon interacts with each system in cascade and the photon paths are mixed by the photon detection. The character of non-exciting of the material qubits does not change the state of material qubit and thus ensures the possibility of purifying entangled states by using more photons under realistic imperfect parameters. It also guarantees directly scaling up the scheme to entangle more qubits. Detailed analysis of fidelity and success probability of the scheme in the frame of an optical Fabry-P\'{e}rot (FP) cavity based strongly coupling system is presented. It is shown that a two-qubit entangled state with fidelity above 0.99 is promised with only two photons by using currently feasible experimental parameters. Our scheme can also be directly implemented on other strongly coupled system.