Hardware-Efficient Leakage-Reduction Scheme for Quantum Error Correction with Superconducting Transmon Qubits

• DOI: 10.1103/prxquantum.2.030314
• Publication Date: 2021-07-26T15:56:50Z
• Authors: F. Battistel; B.M. Varbanov; B.M. Terhal
• Keywords: Transmon; Leakage (economics)

Leakage outside of the qubit computational subspace poses a threatening challenge to quantum error correction (QEC). We propose scheme using two leakage-reduction units (LRUs) that mitigate these issues for transmon-based surface code, without requiring an overhead in terms hardware or QEC-cycle time as previous proposals. For data qubits, we consider microwave drive transfer leakage readout resonator, where it quickly decays, ensuring this negligibly disturbs states realistic system parameters. ancilla apply |1⟩↔|2⟩π pulse conditioned on measurement outcome. Using density-matrix simulations distance-3 show average lifetime is reduced almost one QEC cycle, even when LRUs are implemented with limited fidelity. Furthermore, leads significant reduction logical rate. This LRU opens prospect near-term scalable demonstrations.3 MoreReceived 2 March 2021Revised 16 June 2021Accepted July 2021DOI:https://doi.org/10.1103/PRXQuantum.2.030314Published by American Physical Society under Creative Commons Attribution 4.0 International license. Further distribution work must maintain attribution author(s) and published article's title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasQuantum correctionQuantum information solid state qubitsSurface code computingQuantum Information