Miri Blau, Columbia University: "Scaling Beyond 2 Mode interactions in Quantum Photonic Systems"

Superposition and entanglement are fundamental features of quantum systems. Over the years bipartite entanglement has been analyzed thoroughly and shown to be a vital resource in quantum computation and communication protocols, as is the case for the dual-mode superposition, i.e. qubits. However, extending entanglement into multiple particles, and extending the Hilbert space to higher dimensional superpositions, holds potential yet to be unfolded.
In this talk I will focus on our quantum photonic integrated platform, enabling the generation of frequency-binned single photons and photon pairs. I will present our recent results in mediating linear, beamsplitter-type interactions between several channels simultaneously. We propose a method of achieving simultaneous, all-to-all coupling between N optical frequency modes via N-way Bragg-scattering four-wave mixing. By exploiting the frequency degree of freedom, additional modes can be multiplexed in an interaction medium of fixed volume and loss, avoiding the introduction of excess noise. In addition, I will share our recent progress in generating complex and multi-dimensional, all-photonic cluster states of light. To generate the cluster states, we employ a process which we term "photonic weaving", constructing dual-rail cluster states in time, frequency and polarization. Time- and frequency-binned photons are encoded in polarization to realize a 2xN cluster state. We furthermore show photonic weaving to be extendable to a general NxM cluster state by increasing the number of frequency and time bins, with minimal additional hardware or loss.