Radio frequency measurements of tunnel couplings and singlet-triplet spin states in Si:P quantum dots

M. G. House, T. Kobayashi, B. Weber, S. J. Hile, T. F. Watson, J. Van Der Heijden, S. Rogge, M. Y. Simmons

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Spin states of the electrons and nuclei of phosphorus donors in silicon are strong candidates for quantum information processing applications given their excellent coherence times. Designing a scalable donor-based quantum computer will require both knowledge of the relationship between device geometry and electron tunnel couplings, and a spin readout strategy that uses minimal physical space in the device. Here we use radio frequency reflectometry to measure singlet-triplet states of a few-donor Si:P double quantum dot and demonstrate that the exchange energy can be tuned by at least two orders of magnitude, from 20 μV to 8 meV. We measure dot-lead tunnel rates by analysis of the reflected signal and show that they change from 100 MHz to 22 GHz as the number of electrons on a quantum dot is increased from 1 to 4. These techniques present an approach for characterizing, operating and engineering scalable qubit devices based on donors in silicon.

Original languageEnglish
Article number8848
JournalNature communications
Volume6
DOIs
Publication statusPublished - 2015 Nov 9

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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