Hyperfine interactions in silicon quantum dots

Lucy V. C. Assali, Helena M. Petrilli, Rodrigo B. Capaz, Belita Koiller, Xuedong Hu, S. Das Sarma

Published 2010-07-06, updated 2011-05-07Version 2

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.