In situ scanning gate imaging of individual quantum two-level system defects in live superconducting circuits
Journal article, 2025
The low-temperature physics of structurally amorphous materials is governed by low-energy two-level system (TLS) defects. Being impervious to most traditional condensed matter probes, the exact origin and nature of TLS remain elusive. Recent advances toward realizing stable high-coherence quantum computing platforms have increased the importance of studying TLS in solid-state quantum circuits, as they are a persistent source of decoherence and instability. Here, performing scanning gate microscopy on a live superconducting NbN resonator at millikelvin temperatures, we locate individual TLS, directly revealing their microscopic nature. Mapping and visualizing the most detrimental TLS in the bath pinpoints the dominant sources of ubiquitous 1/f dielectric noise and energy relaxation. We also deduce the three-dimensional orientation of individual TLS electric dipole moments. Combining these insights with structural information of the underlying materials can help unravel the detailed microscopic nature and chemical origin of TLS, directing targeted strategies for their eventual mitigation.
Author
Marius Hegedüs
National Physical Laboratory (NPL)
Royal Holloway University of London
Riju Banerjee
National Physical Laboratory (NPL)
Andrew Hutcheson
National Physical Laboratory (NPL)
Tomas Barker
National Physical Laboratory (NPL)
Sumedh Mahashabde
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Andrey Danilov
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Sergey Kubatkin
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
V. Antonov
Royal Holloway University of London
Sebastian Erik de Graaf
National Physical Laboratory (NPL)
Science advances
2375-2548 (eISSN)
Vol. 11 18 eadt8586Ultima gränsen för känsliga komponenter: Supraledande kvantkrets i form av resonator vid ultralåg temperatur
Swedish Research Council (VR) (2019-05480), 2020-01-01 -- 2023-12-31.
Quantum noise pathfinder
Swedish Research Council (VR) (2020-04393), 2021-01-01 -- 2024-12-31.
Subject Categories (SSIF 2025)
Condensed Matter Physics
DOI
10.1126/sciadv.adt8586
PubMed
40305602