Suppressing the Accumulation of Leakage in Superconducting Circuits for Quantum Error Correction

Despite recent progress in experimental error correction realizations, quantum computers require lower error rates to reach the fault-tolerant regime in which they can outperform standard computers in computational tasks such as simulating quantum systems. One of the dominant errors limiting the performance of quantum error correction codes across multiple technology platforms is leakage out of the computational subspace, originating from the inherent multi-level structure of qubit implementations. In this talk, we present experimental progress towards the mitigation of leakage in targeted experiments with superconducting circuits.