Photon Sorting, Efficient Bell Measurements and a Deterministic CZ Gate using a Passive Two-level Nonlinearity

TL;DR

This paper introduces a novel approach combining strong optical non-linearities with active Gaussian operations to improve the efficiency of Bell state analysis and implement a deterministic CZ gate, overcoming current experimental limitations.

Contribution

It presents a new method that integrates passive two-level nonlinearity with active Gaussian operations for efficient quantum optical devices.

Findings

Enhanced Bell state analysis efficiency

Deterministic implementation of CZ gate

Overcoming limitations of current non-linear optical devices

Abstract

Although the strengths of optical non-linearities available experimentally have been rapidly increasing in recent years, significant challenges remain to using such non-linearities to produce useful quantum devices such as efficient optical Bell state analysers or universal quantum optical gates. Here we describe a new approach that avoids the current limitations by combining strong non-linearities with active Gaussian operations in efficient protocols for Bell state analysers and Controlled-Sign gates.