Quantum Circuit Discovery for Fault-Tolerant Logical State Preparation with Reinforcement Learning

Understand

The realization of large-scale quantum computers requires not only quantum error correction (QEC) but also fault-tolerant operations to handle errors that propagate into harmful errors.

• Recently, flag-based protocols have been introduced that use ancillary qubits to flag harmful errors.
• However, there is no clear recipe for finding a fault-tolerant quantum circuit with flag-based protocols, especially when we consider hardware constraints, such as qubit connectivity and available gate set.
• In this work, we propose and explore reinforcement learning (RL) to automatically discover compact and hardware-adapted fault-tolerant quantum circuits.