Real-Time Adaptive Tracking of Fluctuating Relaxation Rates in Superconducting Qubits
Fabrizio Berritta, Jacob Benestad, Jan A. Krzywda, Oswin Krause, Malthe A. Marciniak, Svend Krøjer, Christopher W. Warren, Emil Hogedal, Andreas Nylander, Irshad Ahmad, Amr Osman, Janka Biznárová, Marcus Rommel, Anita Fadavi Roudsari, Jonas Bylander, Giovanna Tancredi, Jeroen Danon, Jacob Hastrup, Ferdinand Kuemmeth, Morten Kjaergaard
DOI 10.1103/gk1b-stl3 · Physical Review X
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
The fidelity of operations on a solid-state quantum processor is fundamentally bounded by environmental decoherence. Characterizing environmental fluctuations is challenging because the acquisition time of nonadaptive experimental protocols limits temporal precision and can average out rapid features of the underlying dynamics. Here, we overcome this temporal-resolution limit by 2 orders of magnitude using a field-programmable gate-array powered classical controller that adaptively and continuously tracks the relaxation-time fluctuations of two fixed-frequency superconducting transmon qubits, which exhibit average relaxation times of approximately 0.17 ms and occasionally exceed 0.5 ms. We report events in which the relaxation time switches by nearly an order of magnitude over timescales of just tens of milliseconds, rather than minutes or hours as previously reported. Our real-time Bayesian estimation protocol estimates relaxation times within a few milliseconds, close to the decoherence timescale itself. Our statistical analysis further suggests that some of these fast fluctuations arise from two-level systems switching at rates up to 10 Hz, 4 orders of magnitude faster than earlier reports. These results redefine the timescales relevant for calibration in superconducting quantum processing units, establish a reference for rapid relaxation-rate characterization in device screening, and improve our understanding of fast relaxation dynamics.
Similar papers
Fluctuations of Energy-Relaxation Times in Superconducting Qubits
similarity 0.93P. V. Klimov et al.
Source status unknown — claims are unverified
Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits
similarity 0.90Clemens Müller et al.
Source status unknown — claims are unverified
Hot Nonequilibrium Quasiparticles in Transmon Qubits
similarity 0.89K. Serniak et al.
Source status unknown — claims are unverified
Exploiting Dynamic Quantum Circuits in a Quantum Algorithm with Superconducting Qubits
similarity 0.89A. D. Córcoles et al.
Source status unknown — claims are unverified
Macroscopic Tunnel Splittings in Superconducting Phase Qubits
similarity 0.89Philip R. Johnson et al.
Source status unknown — claims are unverified
Fast Accurate State Measurement with Superconducting Qubits
similarity 0.89Evan Jeffrey et al.
Source status unknown — claims are unverified