Reset scheme achieves over 99% fidelity with transmon qubits

Researchers at the Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden; Department of Chemistry, Princeton University, Princeton, NJ, USA; Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA; and VTT Technical Research Centre of Finland, FI-02044 VTT, Finland have demonstrated a protocol for fixed-frequency transmon qubits, an architecture compatible with the surface code, that simultaneously addresses both qubit reset and leakage reduction. This combined capability is desirable for successful quantum error correction. The authors state that experiments involved a pair of qubits. This work reports a complete cycle of qubit reset, leakage reduction, and coupler reset in 83 nanoseconds, enabling fixed-frequency qubit architectures as potential building blocks for future fault-tolerant quantum computers and offering a means to reduce error correction cycle runtime. Over 99% fidelity in qubit reset and leakage reduction has been demonstrated using a novel protocol with fixed-frequency transmon…