Depth-Optimized Reversible Circuit Synthesis

TL;DR

This paper presents a novel cycle-based synthesis algorithm for reversible circuits that reduces circuit depth and cost in quantum architectures with limited interaction, using parallel synthesis of disjoint cycles.

Contribution

Introduces a cycle-based synthesis method with parallel structure and negative controls to optimize depth and cost of reversible circuits in constrained quantum architectures.

Findings

Improved worst-case synthesis cost in linear nearest neighbor architecture.

Effective reduction in circuit depth and cost demonstrated on benchmarks.

Parallel synthesis of disjoint cycles enhances scalability and efficiency.

Abstract

In this paper, simultaneous reduction of circuit depth and synthesis cost of reversible circuits in quantum technologies with limited interaction is addressed. We developed a cycle-based synthesis algorithm which uses negative controls and limited distance between gate lines. To improve circuit depth, a new parallel structure is introduced in which before synthesis a set of disjoint cycles are extracted from the input specification and distributed into some subsets. The cycles of each subset are synthesized independently on different sets of ancillae. Accordingly, each disjoint set can be synthesized by different synthesis methods. Our analysis shows that the best worst-case synthesis cost of reversible circuits in the linear nearest neighbor architecture is improved by the proposed approach. Our experimental results reveal the effectiveness of the proposed approach to reduce cost and circuit depth for several benchmarks.