Scheme for on-chip verification of transverse mode entanglement using the electro-optic effect

TL;DR

This paper proposes an integrated electro-optic device for manipulating and detecting spatial mode entanglement in photons, enabling on-chip Bell inequality tests with potential for quantum technologies.

Contribution

It introduces a novel integrated electro-optic mode converter for deterministic basis transformations in spatial modes, facilitating on-chip quantum entanglement verification.

Findings

Theoretical demonstration of Bell inequality violation using the proposed device.

Numerical analysis confirms feasibility with standard fabrication technology.

Device enables deterministic transformations between non-orthogonal spatial modes.

Abstract

A key ingredient in emerging quantum-enhanced technologies is the ability to coherently manipulate and detect superpositions of basis states. In integrated optics implementations, transverse spatial modes supported by multimode structures offer an attractive carrier of quantum superpositions. Here we propose an integrated dynamic mode converter based on the electro-optic effect in nonlinear channel waveguides for deterministic transformations between mutually non-orthogonal bases of spatial modes. We theoretically show its capability to demonstrate a violation of a Bell-type Clauser-Horne-Shimony-Holt inequality by measuring spatially mode-entangled photon pairs generated by an integrated photon pair source. The proposed configuration, numerically studied for the potassium titanyl phosphate (KTP) material, can be easily implemented using standard integrated optical fabrication technology.