Hybrid Quantum-Classical Photonic Neural Networks

Neuromorphic (brain-inspired) photonics leverages photonic chips to accelerate artificial intelligence, offering high-speed and energy efficient solutions for use in RF communication, tensor processing, and data classification. However, the limited physical size of integrated photonic hardware limits network complexity and computational capacity. In light of recent advance in photonic quantum technology, it is natural to utilize quantum exponential speedup to scale photonic neural network capacity without increasing the network size. Here we show a combination of classical network layers with trainable continuous variable quantum circuits yields hybrid networks with improved trainability and accuracy. On a classification task, hybrid networks achieve the same performance when benchmarked against fully classical networks that are twice the size. When the bit precision of the optimized networks is reduced through added noise, the hybrid networks still achieve greater accuracy when evaluated at state of the art bit precision. These hybrid quantum classical networks demonstrate a unique route to improve computational capacity of integrated photonic neural networks without increasing the network size.