Making Sound with Light: Sound Synthesis with a Photonic Quantum Computer

This chapter reports on the initial results of the authors’ research on developing sound synthesizers with photonic quantum computers. More specifically, it introduces three systems that render sounds from the results of processing photons using Gaussian Boson Sampling (GBS). Essentially, a GBS algorithm normally includes three modules: squeezers, interferometers and photon detectors. In a nutshell, the squeezers prepare the inputs, the interferometer operates on the inputs, and the photon detectors produce the results. Pulses of laser light are input to an array of squeezers. What a squeezer does is crush light into a bunch of photons in a state of superposition, referred to as a squeezed state. Next, squeezed states are relayed to the interferometer. The interferometer provides a network of beam splitters and phase shifters, which are programmed with operations to manipulate the photons. The interferometer is expected to produce highly entangled quantum states encoding the processed quantum information. These are subsequently channelled to detectors that count how many photons are within each stream of squeezed states. The results of the computation are encoded in the statistics of this photon counting. The photon-counting data are used as control parameters for bespoke sound synthesizers.