Divide-et-impera Heuristic-based Randomized Search for the Qubit Routing Problem

TL;DR

The paper presents DIRSH, a heuristic-based randomized divide-and-conquer algorithm for the Qubit Routing Problem, demonstrating improved performance on quantum circuit benchmarks by combining chunk decomposition and bandit heuristics.

Contribution

Introduces DIRSH, a novel heuristic-guided randomized divide-and-conquer approach for QRP, integrating chunk-based decomposition with bandit-driven heuristics.

Findings

DIRSH outperforms LightSABRE variants in depth and swap count.

Effective on RevLib benchmarks mapped to IBMQ Tokyo topology.

Combines chunk decomposition with bandit heuristics for improved routing.

Abstract

This paper introduces the DIRSH algorithm for the Qubit Routing Problem (QRP), using a heuristic-guided randomized divide-and-conquer strategy. The method splits the circuit into chunks and optimizes each one with a stochastic selection of gates and swaps. It balances global search, via restarts and adaptive tuning of bandit parameters with depth-sensitive local pruning. Tested on RevLib benchmarks mapped to the 20-qubit IBMQ Tokyo topology, DIRSH outperformed three LightSABRE variants across different time budgets, achieving shorter depths and fewer swaps. These results confirm that combining chunk-based decomposition with bandit-driven heuristics is effective for routing quantum circuits on NISQ devices.