  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.
