---
OA_place: repository
_id: '22242'
abstract:
- lang: eng
  text: This deposit contains the data and analysis code accompanying the publication
    "Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping
    Hybrid Semiconducting–Superconducting Devices" (Borovkov et al.). The deposit
    includes the raw transport and current-noise measurements of three gate-defined
    quantum-dot devices as QCodes SQLite databases, the master table of the charge-noise
    (flank-method) analysis with the pointers linking every analyzed PSD trace to
    the raw data, the toy-model noise simulation datasets behind the supplementary
    figures, the archived analysis figures (PSD fits and lever-arm extractions), and
    the Python code reproducing the full analysis and all figures. The code is also
    maintained at https://github.com/ISTA-Nanoelectronics/noise_paper_public; instructions
    are provided in the README files.
acknowledged_ssus:
- _id: M-Shop
- _id: NanoFab
article_processing_charge: No
author:
- first_name: Maksim
  full_name: Borovkov, Maksim
  id: 1fd0975f-8b61-11ed-b69e-d149334f28c5
  last_name: Borovkov
citation:
  ama: Borovkov M. Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices. 2026. doi:<a href="https://doi.org/10.15479/AT-ISTA-22242">10.15479/AT-ISTA-22242</a>
  apa: Borovkov, M. (2026). Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices. Institute of Science
    and Technology Austria. <a href="https://doi.org/10.15479/AT-ISTA-22242">https://doi.org/10.15479/AT-ISTA-22242</a>
  chicago: Borovkov, Maksim. “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices.” Institute of Science
    and Technology Austria, 2026. <a href="https://doi.org/10.15479/AT-ISTA-22242">https://doi.org/10.15479/AT-ISTA-22242</a>.
  ieee: M. Borovkov, “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices.” Institute of Science
    and Technology Austria, 2026.
  ista: Borovkov M. 2026. Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices, Institute of Science
    and Technology Austria, <a href="https://doi.org/10.15479/AT-ISTA-22242">10.15479/AT-ISTA-22242</a>.
  mla: Borovkov, Maksim. <i>Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures
    for Prototyping Hybrid Semiconducting-Superconducting Devices</i>. Institute of
    Science and Technology Austria, 2026, doi:<a href="https://doi.org/10.15479/AT-ISTA-22242">10.15479/AT-ISTA-22242</a>.
  short: M. Borovkov, (2026).
contributor:
- contributor_type: contact_person
  first_name: Maksim
  id: 1fd0975f-8b61-11ed-b69e-d149334f28c5
  last_name: Borovkov
corr_author: '1'
date_created: 2026-07-04T17:32:27Z
date_published: 2026-07-04T00:00:00Z
date_updated: 2026-07-06T07:53:56Z
day: '04'
ddc:
- '530'
department:
- _id: GradSch
- _id: GeKa
doi: 10.15479/AT-ISTA-22242
doi_confirm: '1'
file:
- access_level: open_access
  checksum: 2a1ea297e01a7a202a6b144d69a46eef
  content_type: application/x-zip-compressed
  creator: mborovko
  date_created: 2026-07-04T17:28:49Z
  date_updated: 2026-07-04T17:28:49Z
  file_id: '22243'
  file_name: noise_paper_public_deposit.zip
  file_size: 3082596099
  relation: main_file
  success: 1
file_date_updated: 2026-07-04T17:28:49Z
has_accepted_license: '1'
license: https://creativecommons.org/licenses/by/4.0/
month: '07'
oa: 1
oa_version: Published Version
project:
- _id: bdc2ca30-d553-11ed-ba76-cf164a5bb811
  grant_number: '101115315'
  name: Quantum bits with Kitaev Transmons
- _id: 34a66131-11ca-11ed-8bc3-a31681c6b03e
  grant_number: F8606
  name: 'Center for Correlated Quantum Materials and Solid State Quantum Systems:
    Conventional  and unconventional topological superconductors'
- _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a
  grant_number: P36507
  name: Merging spin and superconducting qubits in planar Ge
- _id: 8ea8abf7-16d5-11f0-9cad-c41e56ec8bb3
  grant_number: '101150858'
  name: Realization and Manipulation of a Planar hybrid superconducting Andreev spin
    qubit in Germanium
- _id: 5b9e579c-ab3d-11f0-914f-88754c5b5a3f
  grant_number: PAT 7682124
  name: Superconducting spin qubits in planar Ge
publisher: Institute of Science and Technology Austria
related_material:
  link:
  - relation: research_data
    url: https://github.com/ISTA-Nanoelectronics/noise_paper_public
status: public
title: Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping
  Hybrid Semiconducting-Superconducting Devices
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: research_data
user_id: 68b8ca59-c5b3-11ee-8790-cd641c68093d
year: '2026'
...
---
APC_amount: 3036,92 EUR
DOAJ_listed: '1'
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '19597'
abstract:
- lang: eng
  text: Superconductor–semiconductor hybrid systems play a crucial role in realizing
    nanoscale quantum devices, including hybrid qubits, Majorana bound states, and
    Kitaev chains. For such hybrid devices, subgap states play a prominent role in
    their operation. In this paper, we study these subgap states via Coulomb and tunneling
    spectroscopy through a superconducting island defined in a semiconductor nanowire
    fully coated by a superconductor. We systematically explore regimes ranging from
    an almost decoupled island to the open configuration. In the weak-coupling regime,
    the experimental observations are very similar in the absence of a magnetic field
    and when one flux quantum pierces the superconducting shell. Conversely, in the
    strong-coupling regime, significant distinctions emerge between the two cases.
    We attribute this distinct behavior to the existence of subgap states at one flux
    quantum, which become observable only for sufficiently strong coupling to the
    leads. We support our interpretation using a simple model to describe transport
    through the island. Our study highlights the importance of studying a broad range
    of tunnel couplings for understanding the rich physics of hybrid devices.
acknowledged_ssus:
- _id: M-Shop
- _id: NanoFab
acknowledgement: This research was supported by the Scientific Service Units of ISTA,
  through resources provided by the MIBA Machine Shop and the Nanofabrication facility.
  This research and related results were made possible with the support of the FWF
  Project with DOI10.55776/F86. We acknowledge support from the European Research
  Council under the European Unions Horizon 2020 research and innovation programme
  under Grant Agreement No. 856526, the Swedish Research Council under Grant Agreement
  No. 2020-03412, the Spanish Comunidad de Madrid (CM) “Talento Program” (Project
  No. 2022-T1/IND-24070), the Spanish Ministry of Science, innovation, and Universities
  through Grant PID2022-140552NA-I00 and NanoLund.
article_number: '023022'
article_processing_charge: Yes
article_type: original
author:
- first_name: Marco
  full_name: Valentini, Marco
  id: C0BB2FAC-D767-11E9-B658-BC13E6697425
  last_name: Valentini
- first_name: Rubén Seoane
  full_name: Souto, Rubén Seoane
  last_name: Souto
- first_name: Maksim
  full_name: Borovkov, Maksim
  id: 1fd0975f-8b61-11ed-b69e-d149334f28c5
  last_name: Borovkov
- first_name: Peter
  full_name: Krogstrup, Peter
  last_name: Krogstrup
- first_name: Yigal
  full_name: Meir, Yigal
  last_name: Meir
- first_name: Martin
  full_name: Leijnse, Martin
  last_name: Leijnse
- 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: 'Valentini M, Souto RS, Borovkov M, et al. Subgap transport in superconductor-semiconductor
    hybrid islands: Weak and strong coupling regimes. <i>Physical Review Research</i>.
    2025;7(2). doi:<a href="https://doi.org/10.1103/PhysRevResearch.7.023022">10.1103/PhysRevResearch.7.023022</a>'
  apa: 'Valentini, M., Souto, R. S., Borovkov, M., Krogstrup, P., Meir, Y., Leijnse,
    M., … Katsaros, G. (2025). Subgap transport in superconductor-semiconductor hybrid
    islands: Weak and strong coupling regimes. <i>Physical Review Research</i>. American
    Physical Society. <a href="https://doi.org/10.1103/PhysRevResearch.7.023022">https://doi.org/10.1103/PhysRevResearch.7.023022</a>'
  chicago: 'Valentini, Marco, Rubén Seoane Souto, Maksim Borovkov, Peter Krogstrup,
    Yigal Meir, Martin Leijnse, Jeroen Danon, and Georgios Katsaros. “Subgap Transport
    in Superconductor-Semiconductor Hybrid Islands: Weak and Strong Coupling Regimes.”
    <i>Physical Review Research</i>. American Physical Society, 2025. <a href="https://doi.org/10.1103/PhysRevResearch.7.023022">https://doi.org/10.1103/PhysRevResearch.7.023022</a>.'
  ieee: 'M. Valentini <i>et al.</i>, “Subgap transport in superconductor-semiconductor
    hybrid islands: Weak and strong coupling regimes,” <i>Physical Review Research</i>,
    vol. 7, no. 2. American Physical Society, 2025.'
  ista: 'Valentini M, Souto RS, Borovkov M, Krogstrup P, Meir Y, Leijnse M, Danon
    J, Katsaros G. 2025. Subgap transport in superconductor-semiconductor hybrid islands:
    Weak and strong coupling regimes. Physical Review Research. 7(2), 023022.'
  mla: 'Valentini, Marco, et al. “Subgap Transport in Superconductor-Semiconductor
    Hybrid Islands: Weak and Strong Coupling Regimes.” <i>Physical Review Research</i>,
    vol. 7, no. 2, 023022, American Physical Society, 2025, doi:<a href="https://doi.org/10.1103/PhysRevResearch.7.023022">10.1103/PhysRevResearch.7.023022</a>.'
  short: M. Valentini, R.S. Souto, M. Borovkov, P. Krogstrup, Y. Meir, M. Leijnse,
    J. Danon, G. Katsaros, Physical Review Research 7 (2025).
corr_author: '1'
date_created: 2025-04-20T22:01:28Z
date_published: 2025-04-01T00:00:00Z
date_updated: 2026-06-11T09:13:12Z
day: '01'
ddc:
- '530'
department:
- _id: GeKa
doi: 10.1103/PhysRevResearch.7.023022
file:
- access_level: open_access
  checksum: 535351066e9c900340ef014893a09ac8
  content_type: application/pdf
  creator: dernst
  date_created: 2025-04-22T09:00:08Z
  date_updated: 2025-04-22T09:00:08Z
  file_id: '19604'
  file_name: 2025_PhysReviewResearch_Valentini.pdf
  file_size: 1977581
  relation: main_file
  success: 1
file_date_updated: 2025-04-22T09:00:08Z
has_accepted_license: '1'
intvolume: '         7'
issue: '2'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
project:
- _id: 34a66131-11ca-11ed-8bc3-a31681c6b03e
  grant_number: F8606
  name: 'Center for Correlated Quantum Materials and Solid State Quantum Systems:
    Conventional  and unconventional topological superconductors'
publication: Physical Review Research
publication_identifier:
  issn:
  - 2643-1564
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Subgap transport in superconductor-semiconductor hybrid islands: Weak and
  strong coupling regimes'
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: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 7
year: '2025'
...