---
OA_place: publisher
OA_type: hybrid
_id: '19852'
abstract:
- lang: eng
  text: "Technology involving hybrid superconductor–semiconductor materials is a promising
    avenue for engineering quantum devices for information storage, manipulation,
    and transmission. Proximity-induced superconducting correlations are an essential
    part of such devices. While the proximity effect in the conduction band of common
    semiconductors is well understood, its manifestation in confined hole gases, realized
    for instance in germanium, is an active area of research. Lower-dimensional hole-based
    systems, particularly in germanium, are emerging as an attractive platform for
    a variety of solid-state quantum devices, due to their combination of efficient
    spin and charge control and long coherence times. The recent experimental realization
    of the proximity effect in germanium thus calls for a theoretical description
    that is tailored to hole gases. In this work, we propose a simple model to describe
    proximity-induced superconductivity in two-dimensional hole gases, incorporating
    both the heavy-hole (HH) and light-hole (LH) bands. We start from the Luttinger–Kohn
    model, introduce three parameters that characterize hopping across the superconductor–semiconductor
    interface, and derive explicit intraband and interband effective pairing terms
    for the HH and LH bands. Unlike previous approaches, our theory provides a quantitative
    relationship between induced pairings and interface properties. Restricting our
    general model to an experimentally relevant case where only the HH band crosses
    the chemical potential, we predict the coexistence of \U0001D460-wave and \U0001D451-wave
    singlet pairings, along with triplet-type pairings, and modified Zeeman and Rashba
    spin–orbit couplings. Our results thus present a starting point for theoretical
    modeling of quantum devices based on proximitized hole gases, fueling further
    progress in quantum technology."
acknowledgement: We acknowledge useful discussions with Georgios Katsaros, Andrew
  Higginbotham, and Oliver Schwarze. This research was funded in part by the Austrian
  Science Fund (FWF) F 86, the European Research Council (Grant Agreement No. 856526),
  and by the DFG Collaborative Research Center (CRC) 183 Project No. 277101999.
article_number: '214518'
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Serafim
  full_name: Babkin, Serafim
  id: e63d75c3-72ef-11ef-b75a-e303e149911f
  last_name: Babkin
- first_name: Benjamin
  full_name: Joecker, Benjamin
  last_name: Joecker
- first_name: Karsten
  full_name: Flensberg, Karsten
  last_name: Flensberg
- first_name: Maksym
  full_name: Serbyn, Maksym
  id: 47809E7E-F248-11E8-B48F-1D18A9856A87
  last_name: Serbyn
  orcid: 0000-0002-2399-5827
- first_name: Jeroen
  full_name: Danon, Jeroen
  last_name: Danon
citation:
  ama: Babkin S, Joecker B, Flensberg K, Serbyn M, Danon J. Superconducting proximity
    effect in two-dimensional hole gases. <i>Physical Review B</i>. 2025;111(21).
    doi:<a href="https://doi.org/10.1103/k4jh-pnxy">10.1103/k4jh-pnxy</a>
  apa: Babkin, S., Joecker, B., Flensberg, K., Serbyn, M., &#38; Danon, J. (2025).
    Superconducting proximity effect in two-dimensional hole gases. <i>Physical Review
    B</i>. American Physical Society. <a href="https://doi.org/10.1103/k4jh-pnxy">https://doi.org/10.1103/k4jh-pnxy</a>
  chicago: Babkin, Serafim, Benjamin Joecker, Karsten Flensberg, Maksym Serbyn, and
    Jeroen Danon. “Superconducting Proximity Effect in Two-Dimensional Hole Gases.”
    <i>Physical Review B</i>. American Physical Society, 2025. <a href="https://doi.org/10.1103/k4jh-pnxy">https://doi.org/10.1103/k4jh-pnxy</a>.
  ieee: S. Babkin, B. Joecker, K. Flensberg, M. Serbyn, and J. Danon, “Superconducting
    proximity effect in two-dimensional hole gases,” <i>Physical Review B</i>, vol.
    111, no. 21. American Physical Society, 2025.
  ista: Babkin S, Joecker B, Flensberg K, Serbyn M, Danon J. 2025. Superconducting
    proximity effect in two-dimensional hole gases. Physical Review B. 111(21), 214518.
  mla: Babkin, Serafim, et al. “Superconducting Proximity Effect in Two-Dimensional
    Hole Gases.” <i>Physical Review B</i>, vol. 111, no. 21, 214518, American Physical
    Society, 2025, doi:<a href="https://doi.org/10.1103/k4jh-pnxy">10.1103/k4jh-pnxy</a>.
  short: S. Babkin, B. Joecker, K. Flensberg, M. Serbyn, J. Danon, Physical Review
    B 111 (2025).
corr_author: '1'
date_created: 2025-06-19T16:54:54Z
date_published: 2025-06-18T00:00:00Z
date_updated: 2025-09-30T12:53:47Z
day: '18'
ddc:
- '530'
department:
- _id: MaSe
- _id: GradSch
doi: 10.1103/k4jh-pnxy
external_id:
  arxiv:
  - '2412.04084'
  isi:
  - '001514328000004'
file:
- access_level: open_access
  checksum: fa8757f4780cfaeb51579c626284a8c1
  content_type: application/pdf
  creator: dernst
  date_created: 2025-06-23T10:31:11Z
  date_updated: 2025-06-23T10:31:11Z
  file_id: '19869'
  file_name: 2025_PhysReviewB_Babkin.pdf
  file_size: 1719489
  relation: main_file
  success: 1
file_date_updated: 2025-06-23T10:31:11Z
has_accepted_license: '1'
intvolume: '       111'
isi: 1
issue: '21'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
project:
- _id: 34a7f947-11ca-11ed-8bc3-c5dc2bbaae25
  grant_number: F8609
  name: 'Center for Correlated Quantum Materials and Solid State Quantum Systems:  Probing
    topology in circuits and quantum materials'
publication: Physical Review B
publication_identifier:
  eissn:
  - 2469-9969
  issn:
  - 2469-9950
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Superconducting proximity effect in two-dimensional hole gases
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: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 111
year: '2025'
...