Distributing Quantum Computations, by Shots

Quantum Process Units (QPUs) are becoming more widely accessible to the public. Nonetheless, they still are very susceptible to noise and feature only a small amount of qubits, making it possible to only execute short quantum computations. Facing this problem, several approaches were proposed to make the most of the present situation, either by distributing the Quantum load, sending different Quantum programs to different QPUs or by distributing Quantum program fragments, by cutting a Quantum program into multiple smaller chunks. Here, we propose a change of perspective. Due to the probabilistic nature of Quantum Mechanics, it is usually required to iterate the execution of a Quantum program numerous times or shots. We suggest considering the shots dimension while determining how to distribute quantum computations. In this paper, we design and develop a methodology to distribute the shots of a Quantum program among many QPUs. Exploiting multiple QPUs improves the resilience to potential QPUs failures. Our solution also enables users to directly encode, through a proposed DSL, their own distribution strategies according to their needs and considered scenarios, offering an expressive and customisable approach. Finally, we showcase a prototype implementation and discuss a life-like use case that can only be addressed by relying on our approach.