Experimental access to higher-dimensional entangled quantum systems using integrated optics

TL;DR

This paper demonstrates the generation and control of entangled qutrits using integrated optics, enabling high-dimensional quantum systems on chip with potential for scalable quantum information processing.

Contribution

The authors present a novel integrated optical approach to create and manipulate entangled qutrits, extending capabilities to higher-dimensional quantum systems on chip.

Findings

Successful generation of entangled qutrit states

Complete characterization of two-qutrit EPR correlations

System is scalable to higher dimensions

Abstract

Integrated optics allow the generation and control of increasingly complex photonic states on chip based architectures. Here, we implement two entangled qutrits - a 9-dimensional quantum system - and demonstrate an exceptionally high degree of experimental control. The approach which is conceptually different to common bulk optical implementations is heavily based on methods of integrated in-fiber and on-chip technologies and further motivated by methods commonly used in today's telecommunication industry. The system is composed of an in-fiber source creating entangled qutrit states of any amplitude and phase and an on-chip integrated general Multiport enabling the realization of any desired local unitary transformation within the two qutrit 9-dimensional Hilbert space. The complete design is readily extendible towards higher-dimensions with moderate increase in complexity. Ultimately, our scheme allows for complete on-chip integration. We demonstrate the flexibility and generality of our system by realizing a complete characterization of the two qutrit space of higher-order Einstein-Podolsky-Rosen correlations.