---
_id: '10559'
abstract:
- lang: eng
  text: Hole gases in planar germanium can have high mobilities in combination with
    strong spin-orbit interaction and electrically tunable g factors, and are therefore
    emerging as a promising platform for creating hybrid superconductor-semiconductor
    devices. A key challenge towards hybrid Ge-based quantum technologies is the design
    of high-quality interfaces and superconducting contacts that are robust against
    magnetic fields. In this work, by combining the assets of aluminum, which provides
    good contact to the Ge, and niobium, which has a significant superconducting gap,
    we demonstrate highly transparent low-disordered JoFETs with relatively large
    ICRN products that are capable of withstanding high magnetic fields. We furthermore
    demonstrate the ability of phase-biasing individual JoFETs, opening up an avenue
    to explore topological superconductivity in planar Ge. The persistence of superconductivity
    in the reported hybrid devices beyond 1.8 T paves the way towards integrating
    spin qubits and proximity-induced superconductivity on the same chip.
acknowledged_ssus:
- _id: NanoFab
- _id: M-Shop
acknowledgement: This research and related results were made possible with the support
  of the NOMIS Foundation. This research was supported by the Scientific Service Units
  of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication
  facility, the European Union's Horizon 2020 research and innovation program under
  the Marie Sklodowska-Curie Grant agreement No. 844511 Grant Agreement No. 862046.
  ICN2 acknowledge funding from Generalitat de Catalunya 2017 SGR 327. ICN2 is supported
  by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is
  funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work
  has been performed in the framework of Universitat Autnoma de Barcelona Materials
  Science PhD program. The HAADF-STEM microscopy was conducted in the Laboratorio
  de Microscopias Avanzadas at Instituto de Nanociencia de Aragon-Universidad de Zaragoza.
  Authors acknowledge the LMA-INA for offering access to their instruments and expertise.
  We acknowledge support from CSIC Research Platform on Quantum Technologies PTI-001.
  This project has received funding from the European Union's Horizon 2020 research
  and innovation programme under Grant Agreement No. 823717 ESTEEM3. M.B. acknowledges
  support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020
  FI 00103. G.S. and M.V. acknowledge support through a projectruimte grant associated
  with the Netherlands Organization of Scientific Research (NWO). J.D. acknowledges
  support through FRIPRO-project 274853, which is funded by the Research Council of
  Norway.
article_number: L022005
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Kushagra
  full_name: Aggarwal, Kushagra
  id: b22ab905-3539-11eb-84c3-fc159dcd79cb
  last_name: Aggarwal
  orcid: 0000-0001-9985-9293
- first_name: Andrea C
  full_name: Hofmann, Andrea C
  id: 340F461A-F248-11E8-B48F-1D18A9856A87
  last_name: Hofmann
- first_name: Daniel
  full_name: Jirovec, Daniel
  id: 4C473F58-F248-11E8-B48F-1D18A9856A87
  last_name: Jirovec
  orcid: 0000-0002-7197-4801
- first_name: Ivan
  full_name: Prieto Gonzalez, Ivan
  id: 2A307FE2-F248-11E8-B48F-1D18A9856A87
  last_name: Prieto Gonzalez
  orcid: 0000-0002-7370-5357
- first_name: Amir
  full_name: Sammak, Amir
  last_name: Sammak
- first_name: Marc
  full_name: Botifoll, Marc
  last_name: Botifoll
- first_name: Sara
  full_name: Martí-Sánchez, Sara
  last_name: Martí-Sánchez
- first_name: Menno
  full_name: Veldhorst, Menno
  last_name: Veldhorst
- first_name: Jordi
  full_name: Arbiol, Jordi
  last_name: Arbiol
- first_name: Giordano
  full_name: Scappucci, Giordano
  last_name: Scappucci
- first_name: Jeroen
  full_name: Danon, Jeroen
  last_name: Danon
- first_name: Georgios
  full_name: Katsaros, Georgios
  id: 38DB5788-F248-11E8-B48F-1D18A9856A87
  last_name: Katsaros
  orcid: 0000-0001-8342-202X
citation:
  ama: Aggarwal K, Hofmann AC, Jirovec D, et al. Enhancement of proximity-induced
    superconductivity in a planar Ge hole gas. <i>Physical Review Research</i>. 2021;3(2).
    doi:<a href="https://doi.org/10.1103/physrevresearch.3.l022005">10.1103/physrevresearch.3.l022005</a>
  apa: Aggarwal, K., Hofmann, A. C., Jirovec, D., Prieto Gonzalez, I., Sammak, A.,
    Botifoll, M., … Katsaros, G. (2021). Enhancement of proximity-induced superconductivity
    in a planar Ge hole gas. <i>Physical Review Research</i>. American Physical Society.
    <a href="https://doi.org/10.1103/physrevresearch.3.l022005">https://doi.org/10.1103/physrevresearch.3.l022005</a>
  chicago: Aggarwal, Kushagra, Andrea C Hofmann, Daniel Jirovec, Ivan Prieto Gonzalez,
    Amir Sammak, Marc Botifoll, Sara Martí-Sánchez, et al. “Enhancement of Proximity-Induced
    Superconductivity in a Planar Ge Hole Gas.” <i>Physical Review Research</i>. American
    Physical Society, 2021. <a href="https://doi.org/10.1103/physrevresearch.3.l022005">https://doi.org/10.1103/physrevresearch.3.l022005</a>.
  ieee: K. Aggarwal <i>et al.</i>, “Enhancement of proximity-induced superconductivity
    in a planar Ge hole gas,” <i>Physical Review Research</i>, vol. 3, no. 2. American
    Physical Society, 2021.
  ista: Aggarwal K, Hofmann AC, Jirovec D, Prieto Gonzalez I, Sammak A, Botifoll M,
    Martí-Sánchez S, Veldhorst M, Arbiol J, Scappucci G, Danon J, Katsaros G. 2021.
    Enhancement of proximity-induced superconductivity in a planar Ge hole gas. Physical
    Review Research. 3(2), L022005.
  mla: Aggarwal, Kushagra, et al. “Enhancement of Proximity-Induced Superconductivity
    in a Planar Ge Hole Gas.” <i>Physical Review Research</i>, vol. 3, no. 2, L022005,
    American Physical Society, 2021, doi:<a href="https://doi.org/10.1103/physrevresearch.3.l022005">10.1103/physrevresearch.3.l022005</a>.
  short: K. Aggarwal, A.C. Hofmann, D. Jirovec, I. Prieto Gonzalez, A. Sammak, M.
    Botifoll, S. Martí-Sánchez, M. Veldhorst, J. Arbiol, G. Scappucci, J. Danon, G.
    Katsaros, Physical Review Research 3 (2021).
corr_author: '1'
date_created: 2021-12-16T18:50:57Z
date_published: 2021-04-15T00:00:00Z
date_updated: 2025-04-15T08:38:16Z
day: '15'
ddc:
- '620'
department:
- _id: GeKa
doi: 10.1103/physrevresearch.3.l022005
ec_funded: 1
external_id:
  arxiv:
  - '2012.00322'
file:
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  date_created: 2021-12-17T08:12:37Z
  date_updated: 2021-12-17T08:12:37Z
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file_date_updated: 2021-12-17T08:12:37Z
fulldoi: https://doi.org/10.1103/physrevresearch.3.l022005
has_accepted_license: '1'
intvolume: '         3'
issue: '2'
keyword:
- general engineering
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
project:
- _id: 26A151DA-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '844511'
  name: Majorana bound states in Ge/SiGe heterostructures
- _id: 237E5020-32DE-11EA-91FC-C7463DDC885E
  call_identifier: H2020
  grant_number: '862046'
  name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS
publication: Physical Review Research
publication_identifier:
  issn:
  - 2643-1564
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
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    relation: research_data
    status: public
  - id: '8831'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: Enhancement of proximity-induced superconductivity in a planar Ge hole gas
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 3
year: '2021'
...