Architectures and circuits for distributed quantum computing

TL;DR

This thesis explores architectures and circuits for distributed quantum computing, focusing on compiler strategies to optimize entanglement distribution and improve system fidelity in scalable quantum networks.

Contribution

It introduces rigorous formulations for minimizing the impact of telegates, and applies advanced tools like network optimization and ZX-calculus to enhance distributed quantum systems.

Findings

Formulated methods to optimize telegate impact on fidelity

Identified interdependence between computation and communication

Provided new insights on evolving distributed quantum systems

Abstract

This thesis treats networks providing quantum computation based on distributed paradigms. Compared to architectures relying on one processor, a network promises to be more scalable and less fault-prone. Developing a distributed system able to provide practical quantum computation comes with many challenges, each of which need to be faced with careful analysis in order to create a massive integration of several components properly engineered. In accordance with hardware technologies, currently under construction around the globe, telegates represent the fundamental inter-processor operations. Each telegate consists of several tasks: i) entanglement generation and distribution, ii) local operations, and iii) classical communications. Entanglement generation and distribution is an expensive resource, as it is time-consuming. The main contribution of this thesis is on the definition of compilers that minimize the impact of telegates on the overall fidelity. Specifically, we give rigorous formulations of the subject problem, allowing us to identify the inter-dependence between computation and communication. With the support of some of the best tools for reasoning -- i.e. network optimization, circuit manipulation, group theory and ZX-calculus -- we found new perspectives on the way a distributed quantum computing system should evolve.