aiqbench analysis
This study identifies a critical bottleneck in superconducting quantum processors where readout drive strengths inadvertently shorten qubit lifetimes through interactions with two-level systems and spectral reshaping. By demonstrating that driving at the resonator frequency associated with the qubit ground state minimizes this degradation, the work provides a concrete optimization strategy for improving measurement fidelity without sacrificing speed. These findings offer essential theoretical and experimental guidance for scaling future quantum hardware architectures.
Readout-induced degradation of transmon lifetimes: interplay of TLSs and qubit spectral reshaping
arXiv:2603.13857v2 Announce Type: replace Abstract: Measurement backaction degrades dispersive readout of superconducting qubits even at modest drive strengths, often via the reduction of qubit lifetimes during readout. In this work, we theoretically and experimentally study this degradation and show how it can result from the interplay between detuned two-level systems (TLSs) and a drive-renormalized qubit spectrum. For modest to strong readout, the qubit emission spectrum becomes non-Lorentzian and depends sensitively on the readout drive frequency (even when measurement rate is fixed). We combine the readout-modified qubit emission spectrum with time-dependent perturbation theory to predict qubit lifetimes in the presence of a TLS bath. Master equation simulations and experimental measurements on a frequency-tunable transmon confirm these predictions quantitatively. In particular, we find that driving at the resonator frequency associated with the qubit ground state yields the narrowest qubit emission spectrum and the least lifetime degradation for a fixed measurement rate, providing a practical guideline for optimizing readout protocols in future quantum processors.
Authors:Ziwen Huang, Jimmy Shih-Chun Hung, Mouktik Raha, Ming-Han Chou, Harry Levine, Alex Retzker, Connor T. Hann, David Hover, Fernando G.S.L. Brandão, Aashish A. Clerk, Arbel Haim, Oskar Painter
Abstract:Measurement backaction degrades dispersive readout of superconducting qubits even at modest drive strengths, often via the reduction of qubit lifetimes during readout. In this work, we theoretically and experimentally study this degradation and show how it can result from the interplay between detuned two-level systems (TLSs) and a drive-renormalized qubit spectrum. For modest to strong readout, the qubit emission spectrum becomes non-Lorentzian and depends sensitively on the readout drive frequency (even when measurement rate is fixed). We combine the readout-modified qubit emission spectrum with time-dependent perturbation theory to predict qubit lifetimes in the presence of a TLS bath. Master equation simulations and experimental measurements on a frequency-tunable transmon confirm these predictions quantitatively. In particular, we find that driving at the resonator frequency associated with the qubit ground state yields the narrowest qubit emission spectrum and the least lifetime degradation for a fixed measurement rate, providing a practical guideline for optimizing readout protocols in future quantum processors.
arXiv:2603.13857 [quant-ph]
(or arXiv:2603.13857v2 [quant-ph] for this version)
https://doi.org/10.1103/y5ty-bd4y DOI(s) linking to related resources
Full text under the publisher's open licence · 198 words
Related coverage
New MIT qubit design consists of two strongly coupled modes: one for data storage and one for coupling, allowing faster, higher-fidelity entangling gates and readout
Quantum Zeitgeist · Sep 3, 2026
Quantum error correction avoids pausing with new hardware design
Quantum Zeitgeist · Sep 23, 2026
Tunneling states limit quantum lifetimes in microresonators
Quantum Zeitgeist · Sep 23, 2026
Superconducting circuits host two-level systems with lifetimes exceeding one second
arXiv · Oct 16, 2026