QBX: A Compiler for 2-local Qubit Hamiltonian Simulation on Quantum Chiplets

2026-09-27

AI Summary

This study addresses the lack of high-level semantic optimization and limited scalability in existing Hamiltonian simulation compilers for quantum chip architectures. To this end, it proposes the first hierarchical compiler for 2-local Hamiltonian simulation tailored to multi-chip systems. Methodologically, this work introduces a novel integration of a highway mechanism with multi-target controlled gate aggregation, combined with a scalable hierarchical compilation strategy and a Pauli string aggregation algorithm. These techniques effectively reduce cross-chip communication overhead while accommodating heterogeneous architectures. Experimental evaluations demonstrate that the proposed compiler significantly outperforms existing approaches in both circuit depth and operation count, enabling larger-scale Hamiltonian simulations.

Abstract

2-local qubit Hamiltonian simulation, a fundamental task in quantum computing, is widely applied in various applications. This paper presents QBX, the first quantum compiler designed for 2-local qubit Hamiltonian simulation on quantum chiplet architectures. Existing general-purpose quantum compilers for chiplet architectures target quantum programs at the gate level and miss optimizations requiring high-level semantics of Hamiltonian simulation. Conversely, existing domain-specific compilers for Hamiltonian simulation are designed for monolithic architectures, and their limited scalability and inability to adapt to the heterogeneity of chiplet architectures lead to sub-optimal circuit outputs. QBX implements a scalable hierarchical approach to reduce both the amount and distance of cross-chiplet communications. It integrates the highway mechanism, a chiplet-oriented solution for efficient long-range qubit communication, to diminish cross-chiplet interaction costs. Furthermore, QBX efficiently aggregates 2-local Pauli strings into multi-target controlled gates, harnessing highways for deep optimization. Our evaluations show that QBX markedly outperforms both general-purpose and domain-specific compilers in circuit depth and operation count, while scaling to much larger 2-local Hamiltonian simulations.

Problem

• 2-local qubit Hamiltonian simulation
• quantum chiplets
• quantum compiler
• cross-chiplet communication
• scalability

Innovation

• Quantum Compiler
• Hamiltonian Simulation
• Quantum Chiplets
• Hierarchical Optimization
• Highway Mechanism