Generation of hypercubic cluster states in 1-4 dimensions in a simple optical system

TL;DR

This paper demonstrates a method to generate multi-dimensional optical cluster states using broadband vacuum-squeezed light and electro-optical modulation, enabling scalable quantum entanglement for advanced quantum computing.

Contribution

It introduces a simple optical system to produce 1-4 dimensional hypercubic cluster states with hundreds of entangled modes, advancing scalable quantum state generation.

Findings

Successfully generated up to 4D cluster states with hundreds of modes

Verified entanglement structure using homodyne measurements and covariance matrices

Technique allows scaling of optical cluster states without increased loss

Abstract

Entangled graph states can be used for quantum sensing and computing applications. Error correction in measurement-based quantum computing schemes will require the construction of cluster states in at least 3 dimensions. Here we generate 1-, 2-, 3-, and 4-dimensional optical frequency-mode cluster states by sending broadband 2-mode vacuum-squeezed light through an electro-optical modulator (EOM) driven with multiple frequencies. We create the squeezed light using 4-wave mixing in Rb atomic vapor and mix the sideband frequencies (qumodes) using an EOM, as proposed by Zhu et al. (1), producing a pattern of entanglement correlations that constitute continuous-variable graph states containing up to several hundred qumodes. We verify the entanglement structure by using homodyne measurements to construct the covariance matrices and evaluate the nullifiers. This technique enables scaling of optical cluster states to multiple dimensions without increasing loss.