---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '19424'
abstract:
- lang: eng
  text: "Hole spin qubits are rapidly emerging as the workhorse of semiconducting
    quantum processors because of their large spin-orbit interaction, enabling fast
    all-electric operations at low power. However, spin-orbit interaction also causes
    non-uniformities in devices, resulting in locally varying qubit energies and site-dependent
    anisotropies. While these anisotropies can be used to drive single-spins, if not
    properly harnessed, they can hinder the path toward large-scale quantum processors.
    Here, we report on microwave-driven singlet-triplet qubits in planar germanium
    and use them to investigate the anisotropy of two spins in a double quantum dot.
    We show two distinct operating regimes depending on the magnetic field direction.
    For in-plane fields, the two spins are largely anisotropic, and electrically tunable,
    which enables to measure all the available transitions; coherence times exceeding
    3 $\\mu$s are extracted. For out-of-plane fields, they have an isotropic response
    but preserve the substantial energy difference required to address the singlet-triplet
    qubit. Even in this field direction, where the qubit lifetime\r\nis strongly affected
    by nuclear spins, we find 400 ns coherence times. Our work adds a valuable tool
    to investigate and harness the anisotropy of spin qubits and can be implemented
    in any large-scale NxN device, facilitating the path towards scalable quantum
    processors."
acknowledged_ssus:
- _id: M-Shop
- _id: NanoFab
acknowledgement: "We thank A. Crippa for helpful discussions. 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 NOMIS Foundation, the HORIZON-RIA 101069515 project
  and the FWF Projects with DOI:10.55776/F86 and DOI:10.55776/I5060. M.R.-R. acknowledges
  support from the Netherlands Organization of Scientific Research (NWO) under Veni
  grant VI.Veni.212.223. The\r\nResearch of S.B. and M.R.-R. was sponsored in part
  by the Army Research Office and was accomplished under Award Number: W911NF-23-1-0110.
  The views and conclusions contained in this document are those of the authors and
  should not be interpreted as representing the official policies, either expressed
  or implied, of the Army Research Office or the U.S. Government. The U.S. Government
  is authorized to reproduce and distribute reprints for Government purposes notwithstanding
  any copyright notation herein."
article_number: '3862'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Jaime
  full_name: Saez Mollejo, Jaime
  id: e0390f72-f6e0-11ea-865d-862393336714
  last_name: Saez Mollejo
- first_name: Daniel
  full_name: Jirovec, Daniel
  id: 4C473F58-F248-11E8-B48F-1D18A9856A87
  last_name: Jirovec
  orcid: 0000-0002-7197-4801
- first_name: Yona A
  full_name: Schell, Yona A
  id: fe39122d-06bb-11ec-a33b-9e22b40e40a5
  last_name: Schell
- first_name: Josip
  full_name: Kukucka, Josip
  id: 3F5D8856-F248-11E8-B48F-1D18A9856A87
  last_name: Kukucka
- first_name: Stefano
  full_name: Calcaterra, Stefano
  last_name: Calcaterra
- first_name: Daniel
  full_name: Chrastina, Daniel
  last_name: Chrastina
- first_name: Giovanni
  full_name: Isella, Giovanni
  last_name: Isella
- first_name: Maximilian
  full_name: Rimbach-Russ, Maximilian
  last_name: Rimbach-Russ
- first_name: Stefano
  full_name: Bosco, Stefano
  last_name: Bosco
- first_name: Georgios
  full_name: Katsaros, Georgios
  id: 38DB5788-F248-11E8-B48F-1D18A9856A87
  last_name: Katsaros
  orcid: 0000-0001-8342-202X
citation:
  ama: Saez Mollejo J, Jirovec D, Schell YA, et al. Exchange anisotropies in microwave-driven
    singlet-triplet qubits. <i>Nature Communications</i>. 2025;16. doi:<a href="https://doi.org/10.1038/s41467-025-58969-y">10.1038/s41467-025-58969-y</a>
  apa: Saez Mollejo, J., Jirovec, D., Schell, Y. A., Kukucka, J., Calcaterra, S.,
    Chrastina, D., … Katsaros, G. (2025). Exchange anisotropies in microwave-driven
    singlet-triplet qubits. <i>Nature Communications</i>. Springer Nature. <a href="https://doi.org/10.1038/s41467-025-58969-y">https://doi.org/10.1038/s41467-025-58969-y</a>
  chicago: Saez Mollejo, Jaime, Daniel Jirovec, Yona A Schell, Josip Kukucka, Stefano
    Calcaterra, Daniel Chrastina, Giovanni Isella, Maximilian Rimbach-Russ, Stefano
    Bosco, and Georgios Katsaros. “Exchange Anisotropies in Microwave-Driven Singlet-Triplet
    Qubits.” <i>Nature Communications</i>. Springer Nature, 2025. <a href="https://doi.org/10.1038/s41467-025-58969-y">https://doi.org/10.1038/s41467-025-58969-y</a>.
  ieee: J. Saez Mollejo <i>et al.</i>, “Exchange anisotropies in microwave-driven
    singlet-triplet qubits,” <i>Nature Communications</i>, vol. 16. Springer Nature,
    2025.
  ista: Saez Mollejo J, Jirovec D, Schell YA, Kukucka J, Calcaterra S, Chrastina D,
    Isella G, Rimbach-Russ M, Bosco S, Katsaros G. 2025. Exchange anisotropies in
    microwave-driven singlet-triplet qubits. Nature Communications. 16, 3862.
  mla: Saez Mollejo, Jaime, et al. “Exchange Anisotropies in Microwave-Driven Singlet-Triplet
    Qubits.” <i>Nature Communications</i>, vol. 16, 3862, Springer Nature, 2025, doi:<a
    href="https://doi.org/10.1038/s41467-025-58969-y">10.1038/s41467-025-58969-y</a>.
  short: J. Saez Mollejo, D. Jirovec, Y.A. Schell, J. Kukucka, S. Calcaterra, D. Chrastina,
    G. Isella, M. Rimbach-Russ, S. Bosco, G. Katsaros, Nature Communications 16 (2025).
corr_author: '1'
date_created: 2025-03-19T13:28:12Z
date_published: 2025-04-24T00:00:00Z
date_updated: 2026-04-11T22:30:19Z
day: '24'
ddc:
- '530'
department:
- _id: GeKa
doi: 10.1038/s41467-025-58969-y
external_id:
  arxiv:
  - '2408.03224'
  isi:
  - '001475587400022'
  pmid:
  - '40274808'
file:
- access_level: open_access
  checksum: 13fe84cddc9d4e47213bf17acdac70d7
  content_type: application/pdf
  creator: dernst
  date_created: 2025-05-05T07:08:23Z
  date_updated: 2025-05-05T07:08:23Z
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file_date_updated: 2025-05-05T07:08:23Z
has_accepted_license: '1'
intvolume: '        16'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '04'
oa: 1
oa_version: Published Version
pmid: 1
project:
- _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452
  grant_number: '101069515'
  name: Integrated Germanium Quantum Technology
- _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: c0977eea-5a5b-11eb-8a69-a862db0cf4d1
  grant_number: I05060
  name: High impedance circuit quantum electrodynamics with hole spins
- _id: 262116AA-B435-11E9-9278-68D0E5697425
  name: Hybrid Semiconductor - Superconductor Quantum Devices
publication: Nature Communications
publication_identifier:
  eissn:
  - 2041-1723
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '19409'
    relation: research_data
    status: public
  - id: '19836'
    relation: dissertation_contains
    status: public
scopus_import: '1'
status: public
title: Exchange anisotropies in microwave-driven singlet-triplet qubits
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: 16
year: '2025'
...