Suppressing relaxation in superconducting qubits by quasiparticle pumping

Abstract

Dynamical error suppression techniques are commonly used to improve coherence in quantum systems. They reduce dephasing errors by applying control pulses designed to reverse erroneous coherent evolution driven by environmental noise. However, such methods cannot correct for irreversible processes such as energy relaxation. In this work, we investigate a complementary, stochastic approach to reducing errors: instead of deterministically reversing the unwanted qubit evolution, we use control pulses to shape the noise environment dynamically. In the context of superconducting qubits, we implement a pumping sequence to reduce the number of unpaired electrons (quasiparticles) in close proximity to the device. We report a 70% reduction in the quasiparticle density, resulting in a threefold enhancement in qubit relaxation times, and a comparable reduction in coherence variability.

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Cited by in corpus (6)

• Decoherence benchmarking of superconducting qubits
• Low-Loss Superconducting Nanowire Circuits Using a Neon Focused Ion Beam
• Optimal configurations for normal-metal traps in transmon qubits
• Entropy production in a photovoltaic cell
• Continuous Real-Time Detection of Quasiparticle Trapping in Aluminum Nanobridge Josephson Junctions
• Material matters in superconducting qubits