Recovery dynamics of a gap-engineered transmon after a quasiparticle burst

• URL: http://arxiv.org/abs/2505.08104v2
• Date: Wed, 11 Jun 2025 02:15:24 GMT
• Title: Recovery dynamics of a gap-engineered transmon after a quasiparticle burst
• Authors: Heekun Nho, Thomas Connolly, Pavel D. Kurilovich, Spencer Diamond, Charlotte G. L. Bøttcher, Leonid I. Glazman, Michel H. Devoret,
• Abstract summary: Ionizing radiation impacts create bursts of quasiparticle density in superconducting qubits.<n>These bursts temporarily degrade qubit coherence which can be detrimental for quantum error correction.<n>We experimentally resolve quasiparticle bursts in 3D gap-engineered transmon qubits by continuously monitoring qubit transitions.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Ionizing radiation impacts create bursts of quasiparticle density in superconducting qubits. These bursts temporarily degrade qubit coherence which can be detrimental for quantum error correction. Here, we experimentally resolve quasiparticle bursts in 3D gap-engineered transmon qubits by continuously monitoring qubit transitions. Gap engineering allowed us to reduce the burst detection rate by a factor of a few. This reduction falls several orders of magnitude short of that expected if the quasiparticles were to quickly thermalize to the cryostat temperature. We associate the limited effect of gap engineering with the slow thermalization of the phonons in our chips after the burst.

Related papers

• Modeling phonon-mediated quasiparticle poisoning in superconducting qubit arrays [0.0]
  Correlated errors caused by ionizing radiation impacting superconducting qubit chips are problematic for quantum error correction. We describe a comprehensive strategy for the numerical simulation of the phonon and quasiparticle dynamics in the aftermath of an impact.
  arXiv  Detail & Related papers  (2024-02-23T18:02:51Z)
• Suppression of quasiparticle poisoning in transmon qubits by gap engineering [0.0]
  Inelastic quasiparticle tunneling across Josephson junctions in superconducting qubits results in decoherence and spurious excitations. We use "gap engineering" to suppress the tunneling of low-energy quasiparticles in Al-based transmon qubits. The suppression of QP tunneling also results in a reduction in the qubit energy relaxation rates.
  arXiv  Detail & Related papers  (2023-09-06T01:59:53Z)
• Enhancing the Coherence of Superconducting Quantum Bits with Electric Fields [62.997667081978825]
  We show that qubit coherence can be improved by tuning defects away from the qubit resonance using an applied DC-electric field. We also discuss how local gate electrodes can be implemented in superconducting quantum processors to enable simultaneous in-situ coherence optimization of individual qubits.
  arXiv  Detail & Related papers  (2022-08-02T16:18:30Z)
• Stabilizing and improving qubit coherence by engineering noise spectrum of two-level systems [52.77024349608834]
  Superconducting circuits are a leading platform for quantum computing. Charge fluctuators inside amorphous oxide layers contribute to both low-frequency $1/f$ charge noise and high-frequency dielectric loss. We propose to mitigate those harmful effects by engineering the relevant TLS noise spectral densities.
  arXiv  Detail & Related papers  (2022-06-21T18:37:38Z)
• Engineering superconducting qubits to reduce quasiparticles and charge noise [14.613106897690752]
  We experimentally demonstrate how to control quasiparticle generation by downsizing the qubit. We shape the electromagnetic environment of the qubit above the superconducting gap, inhibiting quasiparticle poisoning. Our findings support the hypothesis that quasiparticle generation is dominated by the breaking of Cooper pairs at the junction.
  arXiv  Detail & Related papers  (2022-02-03T06:40:21Z)
• Continuous Real-Time Detection of Quasiparticle Trapping in Aluminum Nanobridge Josephson Junctions [5.912792105701256]
  Nonequilibrium quasiparticles are ubiquitous in superconducting electronics. We characterize a quasiparticle trapping detector device based on a two-junction aluminum nanobridge superconducting quantum interference device incorporated into a transmission-line resonator. We demonstrate continuous detection of up to 3 trapped quasiparticles, with detection of a trapped quasiparticle with signal-to-noise ratio of 27 in 5 $mu$s.
  arXiv  Detail & Related papers  (2021-07-15T05:09:25Z)
• Intrinsic mechanisms for drive-dependent Purcell decay in superconducting quantum circuits [68.8204255655161]
  We find that in a wide range of settings, the cavity-qubit detuning controls whether a non-zero photonic population increases or decreases qubit decay Purcell. Our method combines insights from a Keldysh treatment of the system, and Lindblad theory.
  arXiv  Detail & Related papers  (2021-06-09T16:21:31Z)
• A superconductor free of quasiparticles for seconds [0.0]
  We experimentally demonstrate a superconductor completely free of quasiparticles for periods lasting up to seconds. Our results demonstrate the possibility of operating devices without quasiparticles with potentially improved performance.
  arXiv  Detail & Related papers  (2021-01-31T16:29:34Z)
• Probing the coherence of solid-state qubits at avoided crossings [51.805457601192614]
  We study the quantum dynamics of paramagnetic defects interacting with a nuclear spin bath at avoided crossings. The proposed theoretical approach paves the way to designing the coherence properties of spin qubits from first principles.
  arXiv  Detail & Related papers  (2020-10-21T15:37:59Z)
• Dissipative-coupling-assisted laser cooling: limitations and perspectives [91.3755431537592]
  We present a comprehensive analysis of a protocol which reveals its very high sensitivity to small imperfections such as an additional dissipation. A detailed comparison of the cooling protocol in question with the dispersive-coupling-assisted protocols which use the red sideband excitation or feedback is presented.
  arXiv  Detail & Related papers  (2020-07-27T16:02:16Z)
• Reducing the impact of radioactivity on quantum circuits in a deep-underground facility [0.36954891170556703]
  Coherence times of superconducting circuits have increased from nanoseconds to hundreds of microseconds. Coherence needs to further improve by orders of magnitude to reduce the prohibitive hardware overhead of current error correction schemes. We show that environmental radioactivity is a significant source of nonequilibrium quasiparticles.
  arXiv  Detail & Related papers  (2020-05-05T15:37:43Z)
• Decoherence as Detector of the Unruh Effect [58.720142291102135]
  We propose a new type of the Unruh-DeWitt detector which measures the decoherence of the reduced density matrix of the detector interacting with the massless quantum scalar field. We find that the decoherence decay rates are different in the inertial and accelerated reference frames.
  arXiv  Detail & Related papers  (2020-03-10T21:45:09Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.