Hyperfine interactions in silicon quantum dots

TL;DR

This paper provides detailed calculations of hyperfine interactions in silicon quantum dots, highlighting their favorable properties for spin coherence and potential in spintronic applications.

Contribution

It offers an all-electron calculation of hyperfine parameters in silicon, revealing their scaling, magnitude, and implications for quantum dot spin coherence.

Findings

Hyperfine parameters scale linearly with spin density.

Isotropic hyperfine term is over 30 times larger than anisotropic.

Overhauser fields in Si QDs are much smaller than in GaAs QDs.

Abstract

We present an all-electron calculation of the hyperfine parameters for conduction electrons in Si, showing that: (i) all parameters scale linearly with the spin density at a $^{29}$Si site; (ii) the isotropic term is over 30 times larger than the anisotropic part; (iii) conduction electron charge density at a Si nucleus is consistent with experimental estimates; (iv) Overhauser fields in natural Si quantum dots (QDs) are two orders of magnitude smaller than in GaAs QDs. This reinforces the outstanding performance of Si in keeping spin coherence and opens access to reliable quantitative information aiming at spintronic applications.