All optical Controlled-NOT quantum gate based on an exciton-polariton circuit

TL;DR

This paper proposes a novel all-optical CNOT quantum gate using a patterned microcavity polariton system, encoding qubits in polariton spins and utilizing spin interactions for quantum logic operations.

Contribution

It introduces a practical design for a CNOT gate based on exciton-polariton circuits, leveraging modern fabrication techniques and spin-dependent interactions.

Findings

Design of a polariton-based CNOT gate with specific cavity structure

Use of spin-orbit effects to control qubit states

Potential for integration with existing photonic technologies

Abstract

We propose an implementation of a CNOT quantum gate for quantum computing based on a patterned microcavity polariton system, which can be manufactured using the modern technological facilities. The qubits are encoded in the spin of polaritons. The structure consists of two wire cavities oriented at 45 degrees with a micropillar between them. The polariton spin rotates due to the Longitudinal-Transverse splitting between polarisation eigenstates in the wires. In the pillar, the optically generated circularly polarised polariton macrooccupied state plays the role of the control qubit. Because of the spin-anisotropic polariton interaction, it induces an effective magnetic field along the Z-direction with a sign depending on the qubit value.