Two-Qubit Geometric Phase Gate for Quantum Dot Spins using Cavity Polariton Resonance

TL;DR

This paper proposes a high-speed, high-fidelity two-qubit geometric phase gate for quantum dot spins, utilizing cavity polariton resonance and Coulomb exchange interactions to enable scalable quantum entanglement.

Contribution

It introduces a novel optical coupling mechanism resembling RKKY interactions for entangling quantum dot spins via exciton-polaritons, optimizing parameters for minimal error.

Findings

High fidelity two-qubit gate operation demonstrated

Optimization reduces errors from polariton lifetime limitations

Design maximizes entanglement and scalability

Abstract

We describe a design to implement a two-qubit geometric phase gate, by which a pair of electrons confined in adjacent quantum dots are entangled. The entanglement is a result of the Coulomb exchange interaction between the optically excited exciton-polaritons and the localized spins. This optical coupling, resembling the electron-electron Ruderman-Kittel-Kasuya-Yosida (RKKY) inter- actions, offers high speed, high fidelity two-qubit gate operation with moderate cavity quality factor Q. The errors due to the finite lifetime of the polaritons can be minimized by optimizing the optical pulse parameters (duration and energy). The proposed design, using electrostatic quantum dots, maximizes entanglement and ensures scalability.