The origins of noise in the Zeeman splitting of spin qubits in natural-silicon devices
We measure and analyze noise-induced energy-fluctuations of spin qubits defined in quantum dots made of isotopically natural silicon. Combining Ramsey, time-correlation of single-shot measurements, and CPMG experiments, we cover the qubit noise power spectrum over a frequency range of nine orders of magnitude without any gaps. We find that the low-frequency noise spectrum is similar across three different devices suggesting that it is dominated by the hyperfine coupling to nuclei. The effects of charge noise are smaller, but not negligible, and are device dependent as confirmed from the noise cross-correlations. We also observe differences to spectra reported in GaAs [Phys. Rev. Lett. 118, 177702 (2017), Phys. Rev. Lett. 101, 236803 (2008)], which we attribute to the presence of the valley degree of freedom in silicon. Finally, we observe <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup><mml:mrow><mml:mi>T</mml:mi></mml:mrow> <mml:mrow><mml:mn>2</mml:mn></mml:mrow> <mml:mrow><mml:mo>*</mml:mo></mml:mrow> </mml:msubsup> </mml:math> to increase upon increasing the external magnetic field, which we speculate is due to the increasing field gradient of the micromagnet suppressing nuclear spin diffusion.
Authors
- Seigo Tarucha (ORCID: https://orcid.org/0000-0001-7465-0135)
- Yohei Kojima (ORCID: https://orcid.org/0000-0003-4790-6312)
- Kenta Takeda (ORCID: https://orcid.org/0000-0003-1240-1103)
- Daniel Loss (ORCID: https://orcid.org/0000-0001-5176-3073)
- Peter Stano (ORCID: https://orcid.org/0000-0001-5835-0765)
- Juan S. Rojas-Arias (ORCID: https://orcid.org/0000-0003-3669-0288)
- Akito Noiri (ORCID: https://orcid.org/0000-0001-9145-0303)
- Takashi Kobayashi (ORCID: https://orcid.org/0000-0003-2841-8129)
- Takashi Nakajima (ORCID: https://orcid.org/0000-0002-6861-731X)
- Jun Yoneda (ORCID: https://orcid.org/0000-0003-0743-3696)
Institutions
- Tokyo University of Science (JP)
- University of Basel (CH)
- Slovak Academy of Sciences (SK)
- RIKEN Center for Emergent Matter Science (JP)
- Institute of Physics of the Slovak Academy of Sciences (SK)
- RIKEN Center for Advanced Photonics (JP)
- Advanced Institute of Industrial Technology (JP)
- The University of Tokyo (JP)
Publication Details
- Journal
- npj Quantum Information
- Published
- 2025-12-09
- DOI
- https://doi.org/10.1038/s41534-025-01150-6
- Citations
- 2
- Primary Topic
- Quantum and electron transport phenomena
- Type
- article
- Field-Weighted Citation Impact
- 2.49
Funders
- National Science Foundation
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Japan Society for the Promotion of Science
- Core Research for Evolutional Science and Technology
- Precursory Research for Embryonic Science and Technology
- Moonshot Research and Development Program