A Compilation Framework for Quantum Simulation of Non-unitary Dynamics

2026-05-22

AI Summary

Existing quantum compilers primarily target unitary circuits and struggle to efficiently simulate the non-unitary dynamics inherent in open quantum systems. This work proposes the first compilation framework that treats quantum channels as first-class objects, introducing ChannelIR—a novel intermediate representation that explicitly models Kraus operators. By integrating Pauli- and algebra-based rewriting with structure-aware circuit synthesis, the framework enables end-to-end compilation from Lindbladian generators to optimized gate-level circuits. Evaluated on standard benchmarks, the approach reduces gate counts by up to 99% compared to state-of-the-art methods based on Stinespring dilation, demonstrating significantly improved scalability and practicality for simulating open quantum dynamics.

Abstract

Most quantum compilers assume programs are reversible unitary circuits. This fits closed-system algorithms, but not open-system simulation, where the natural program objects are quantum channels describing non-unitary dynamics. We present a channel-first compilation framework that treats channels as first-class compilation objects. Our core IR, ChannelIR, represents channels explicitly in Kraus form, a standard channel representation, with Pauli-sum structure, enabling algebraic rewrites before circuit synthesis. We instantiate the framework with LindFront, a frontend that lowers continuous-time Lindbladian generators to short-time channels, and a backend that compiles these channels to executable circuits with structure-aware optimizations. On Lindbladian and channel-simulation benchmarks, the optimized pipeline reduces gate count by up to 99% over an unoptimized channel-first baseline and scales better than circuit-first Stinespring compilation.

Problem

• quantum simulation
• non-unitary dynamics
• quantum channels
• open quantum systems
• quantum compilation

Innovation

• quantum channel
• non-unitary dynamics
• Kraus representation
• Lindbladian simulation
• quantum compilation