Discovering Quantum Circuits for Logical State Preparation with Deep Reinforcement Learning

Remmy Zen, Jan Olle, Matteo Puviani, Florian Marquardt

Abstract: Quantum error correction (QEC) is important for the realization of fault-tolerant quantum computers. The first essential step of QEC is to encode the logical state into physical qubits. However, there is no unique recipe for finding a quantum circuit that encodes or prepares the logical state, especially for a given gate set and qubit connectivity. In this work, we use deep reinforcement learning to automatically discover quantum circuits to prepare the logical state of a QEC code given a gate set and qubit connectivity. We show that our method can prepare a logical state of up to 17 physical qubits code in fully connected qubits and up to 15 physical qubits code with IBM quantum devices gate set and connectivity with smaller circuit size than other methods.