A Lazy Resynthesis Approach for Simultaneous T Gate and Two-Qubit Gate Optimization of Quantum Circuits

IEEE QCE 2025 2025

Authors: Mu-Te Lau, Hsiang-Chun Yang, Hsin-Yu Chen, Chung-Yang Huang

Abstract

State-of-the-art quantum circuit optimization (QCO) algorithms for T-count reduction often lead to a substantial increase in two-qubit gate count (2Q-count) -- a drawback that existing 2Q-count optimization techniques struggle to address effectively. In this work, we propose a novel lazy resynthesis approach for modern tableau-based QCO flows that significantly mitigates the 2Q-gate surges commonly introduced during T-count optimization in Clifford+T circuits. Experimental results show that our approach reduces 2Q-count overhead by 54.8%, 15.3%, and 68.0% compared to tableau-based, ZX-calculus-based, and path-sum-based QCO algorithms, respectively.