Radio frequency measurements of tunnel couplings and singlet-triplet spin states in Si:P quantum dots.
Nat Commun
; 6: 8848, 2015 Nov 09.
Article
em En
| MEDLINE
| ID: mdl-26548556
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 SiP double quantum dot and demonstrate that the exchange energy can be tuned by at least two orders of magnitude, from 20 µeV 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.
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MEDLINE
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En
Ano de publicação:
2015
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Article