Title: Integrated Photonic Quantum Information Processing

Abstract: 
Photonics is one of the leading platforms for quantum information processing, due to its scalability, ability to operate at room temperature, and compatibility with the existing telecom industry. In photonic QIP, information is loaded onto a degree of freedom of photons, which is then manipulated to achieve information processing. In our case, the degree of freedom is position, and we achieve the manipulation using integrated photonics. In this talk, I will discuss various efforts which my team has carried out on this topic over the years.

First, I will focus on near-term quantum applications, suitable for near-term devices. I will present an algorithm that uses a small photonic quantum computer as a co-processor for Monte Carlo integration. I will show an implementation of this algorithm on existing quantum photonic hardware.

Second, I will discuss my group’s efforts to facilitate large-scale quantum computation in conjunction with QuiX Quantum. I will present a novel component which we invented for a photonic quantum computer. The component uses measurement and feedback to probabilistically improve the quality of single photons. I will demonstrate that this component reduces the bill of materials of a large scale quantum computer by roughly a factor of 2 to 5, depending on the precise assumptions used.

Third, I will present a novel intuition for circuit design in planar integrated photonic chips. It is commonly believed that in such circuits, balanced loss – which is achieved through a symmetric arrangement of beam splitters and phase shifters – is the optimal choice. I will show instead that for many quantum computing applications a maximally unbalanced circuit is optimal.