---
res:
  bibo_abstract:
  - State-of-the-art transmon qubits rely on large capacitors, which systematically
    improve their coherence due to reduced surface-loss participation. However, this
    approach increases both the footprint and the parasitic cross-coupling and is
    ultimately limited by radiation losses—a potential roadblock for scaling up quantum
    processors to millions of qubits. In this work we present transmon qubits with
    sizes as low as 36 × 39 µm2 with  100-nm-wide vacuum-gap capacitors that are micromachined
    from commercial silicon-on-insulator wafers and shadow evaporated with aluminum.
    We achieve a vacuum participation ratio up to 99.6% in an in-plane design that
    is compatible with standard coplanar circuits. Qubit relaxationtime measurements
    for small gaps with high zero-point electric field variance of up to 22 V/m reveal
    a double exponential decay indicating comparably strong qubit interaction with
    long-lived two-level systems. The exceptionally high selectivity of up to 20 dB
    to the superconductor-vacuum interface allows us to precisely back out the sub-single-photon
    dielectric loss tangent of aluminum oxide previously exposed to ambient conditions.
    In terms of future scaling potential, we achieve a ratio of qubit quality factor
    to a footprint area equal to 20 µm−2, which is comparable with the highest T1
    devices relying on larger geometries, a value that could improve substantially
    for lower surface-loss superconductors. @eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Martin
      foaf_name: Zemlicka, Martin
      foaf_surname: Zemlicka
      foaf_workInfoHomepage: http://www.librecat.org/personId=2DCF8DE6-F248-11E8-B48F-1D18A9856A87
    orcid: 0009-0005-0878-3032
  - foaf_Person:
      foaf_givenName: Elena
      foaf_name: Redchenko, Elena
      foaf_surname: Redchenko
      foaf_workInfoHomepage: http://www.librecat.org/personId=2C21D6E8-F248-11E8-B48F-1D18A9856A87
  - foaf_Person:
      foaf_givenName: Matilda
      foaf_name: Peruzzo, Matilda
      foaf_surname: Peruzzo
      foaf_workInfoHomepage: http://www.librecat.org/personId=3F920B30-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0002-3415-4628
  - foaf_Person:
      foaf_givenName: Farid
      foaf_name: Hassani, Farid
      foaf_surname: Hassani
      foaf_workInfoHomepage: http://www.librecat.org/personId=2AED110C-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0001-6937-5773
  - foaf_Person:
      foaf_givenName: Andrea
      foaf_name: Trioni, Andrea
      foaf_surname: Trioni
      foaf_workInfoHomepage: http://www.librecat.org/personId=42F71B44-F248-11E8-B48F-1D18A9856A87
  - foaf_Person:
      foaf_givenName: Shabir
      foaf_name: Barzanjeh, Shabir
      foaf_surname: Barzanjeh
      foaf_workInfoHomepage: http://www.librecat.org/personId=2D25E1F6-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0003-0415-1423
  - foaf_Person:
      foaf_givenName: Johannes M
      foaf_name: Fink, Johannes M
      foaf_surname: Fink
      foaf_workInfoHomepage: http://www.librecat.org/personId=4B591CBA-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0001-8112-028X
  bibo_doi: 10.1103/PhysRevApplied.20.044054
  bibo_issue: '4'
  bibo_volume: 20
  dct_date: 2023^xs_gYear
  dct_identifier:
  - UT:001095315600001
  dct_isPartOf:
  - http://id.crossref.org/issn/2331-7019
  dct_language: eng
  dct_publisher: American Physical Society@
  dct_title: 'Compact vacuum-gap transmon qubits: Selective and sensitive probes for
    superconductor surface losses@'
...