Cut&Shoot: Cutting & Distributing Quantum Circuits Across Multiple NISQ Computers

Currently, quantum researchers are facing the limitations of NISQ (Noisy Intermediate-Scale Quantum) computers, such as limited qubit counts and high sensitivity to external interference. In response to these challenges, two techniques have recently been proposed, among others, to enhance the execution of quantum circuits: circuit cutting and shot-wise distribution. Circuit cutting partitions large quantum circuits into smaller fragments that can be executed on today's NISQ devices. Shot-wise distribution leverages multiple heterogeneous quantum computers by distributing the shots of a single quantum circuit execution across various NISQ devices, improving resiliency and reducing overall execution time, in a flexible and customisable way. In this work, we investigate the synergic effect of a seamless composition of these two techniques into a unified pipeline of our own design, termed Cut&Shoot. This pipeline fragments a single quantum circuit into multiple independent sub-circuits, distributes the shots of each fragment across various quantum computers, and finally merges the results to reconstruct the output for the original circuit. Noisy simulation experiments seem to indicate that circuit cutting effectively reduces error rates, without the need to increase the number of shots performed. Shot-wise distribution, instead, while offering several qualitative advantages, does not significantly affect error rates, with negligible time overhead.