Photonic multipartite entanglement in discrete variables without arbitrary unitaries

TL;DR

This paper introduces a versatile method for creating multipartite photonic entangled states using photon-pair sources, enabling flexible design of high-dimensional GHZ states on-chip without complex unitaries.

Contribution

It proposes a general approach for designing multipartite entangled photon sources applicable across various platforms and encoding schemes, simplifying implementation by avoiding complex optical components.

Findings

Designed a passive integrated source of high-dimensional GHZ states

Achieved a 10 kHz on-chip generation rate

Applicable to arbitrary target states and encoding schemes

Abstract

We present an approach for designing sources of postselected multipartite states based on photon-pair sources. Our approach can be applied to arbitrary target states in different encoding schemes and physical platforms. It also allows one to limit the types of components to be used in the device, such that lossy or difficult-to-implement optical elements can be avoided. As an example, we apply this strategy to design a passive integrated source of frequency-bin-encoded high-dimensional GHZ states with a 10 kHz on-chip generation rate for picojoule pump pulses.