Simultaneous execution of quantum circuits on current and near-future NISQ systems

TL;DR

This paper introduces palloq, a method for improving multi-programming of quantum circuits on NISQ systems by optimizing layout and reducing crosstalk, with a protocol for hardware suitability assessment.

Contribution

It presents palloq, a novel approach for concurrent quantum circuit execution that considers layout and crosstalk, along with a software-based crosstalk detection protocol.

Findings

Trade-off identified between success rate and execution time.

palloq improves performance of quantum multi-programming.

Effective crosstalk characterization protocol developed.

Abstract

In the NISQ era, multi-programming of quantum circuits (QC) helps to improve the throughput of quantum computation. Although the crosstalk, which is a major source of noise on NISQ processors, may cause performance degradation of concurrent execution of multiple QCs, its characterization cost grows quadratically in processor size. To address these challenges, we introduce palloq (parallel allocation of QCs) for improving the performance of quantum multi-programming on NISQ processors while paying attention to the combination of QCs in parallel execution and their layout on the quantum processor, and reducing unwanted interference between QCs caused by crosstalk. We also propose a software-based crosstalk detection protocol that efficiently and successfully characterizes the hardware's suitability for multi-programming. We found a trade-off between the success rate and execution time of the multi-programming. This would be attractive not only to quantum computer service but also to users around the world who want to run algorithms of suitable scale on NISQ processors that have recently attracted great attention and are being enthusiastically investigated.