Deterministic Fault-Tolerant State Preparation for Near-Term Quantum Error Correction: Automatic Synthesis Using Boolean Satisfiability

TL;DR

This paper introduces an automated method using satisfiability solving to synthesize fault-tolerant quantum circuits for state preparation, enhancing near-term quantum error correction with open-source tools.

Contribution

It presents the first automated synthesis approach for fault-tolerant state preparation circuits applicable to near-term quantum codes, leveraging classical circuit design techniques.

Findings

Synthesized circuits exhibit correct fault-tolerant behavior in simulations.

The approach is applicable to a broad class of quantum codes.

All routines are available as open-source software.

Abstract

To ensure resilience against the unavoidable noise in quantum computers, quantum information needs to be encoded using an error-correcting code, and circuits must have a particular structure to be fault-tolerant. Compilation of fault-tolerant quantum circuits is thus inherently different from the non-fault-tolerant case. However, automated fault-tolerant compilation methods are widely underexplored, and most known constructions are obtained manually for specific codes only. In this work, we focus on the problem of automatically synthesizing fault-tolerant circuits for the deterministic initialization of an encoded state for a broad class of quantum codes that are realizable on current and near-term hardware. To this end, we utilize methods based on techniques from classical circuit design, such as satisfiability solving, resulting in tools for the synthesis of (optimal) fault-tolerant state preparation circuits for near-term quantum codes. We demonstrate the correct fault-tolerant behavior of the synthesized circuits using circuit-level noise simulations. We provide all routines as open-source software as part of the Munich Quantum Toolkit (MQT) at https://github.com/cda-tum/mqt-qecc.