GTQCP: Greedy Topology-Aware Quantum Circuit Partitioning

TL;DR

The paper tackles the challenge of partitioning large quantum circuits for peephole optimization on NISQ devices by dividing circuits into subcircuits containing at most $k$ qubits. It introduces GTQCP, a greedy topology-aware gate partitioning method that builds a qubit dependency graph and greedily enumerates candidate qubit groups into partitions. GTQCP achieves partition quality nearly identical to high-quality baselines (ScanPartitioner and PreviousPaper) while delivering substantial runtime improvements over QuickPartitioner ($38\%$ quality advantage; run-time improvements of $18\%$, $96\%$, and $70\%$ respectively), and a worst-case bound of $O(g n e^{k/e})$. Benchmarks across varied circuits show stable performance for larger $k$ and demonstrate practical applicability to scalable quantum circuit synthesis.

Abstract

We propose Greedy Topology-Aware Quantum Circuit Partitioning (GTQCP), a novel quantum gate circuit partitioning method which partitions circuits by applying a greedy heuristic to the qubit dependency graph of the circuit. GTQCP is compared against three other gate partitioning methods, two of which (QuickPartitioner and ScanPartitioner) are part of the Berkley Quantum Synthesis Toolkit. GTQCP is shown to have 18% run time improvement ratio over the fastest approach (QuickPartitioner), and a 96% improvement over the highest quality approach (ScanPartitioner). The algorithm also demonstrates nearly identical result quality (number of partitions) compared with ScanPartitioner, and a 38% quality improvement over QuickPartitioner.

Figures (4)

• Figure 1: Converting a Quantum Circuit into a Direct Acyclic Graph
• Figure 2: Gate Dependency Calculation
• Figure 3: Group Enumeration Steps on Example Circuit for Qubit 3
• Figure 4: Performance for Partitioning Methods Across Select Benchmarks