Zero Spin Silicon- Quantum Computers, page-3

The transcript of the Michelle Simmons lecture is in the .pdf below:

02 The Quantum Promise - ABC listen - part 2.pdf

Silex zero spin is not mentioned but Michelle does refer to the natural crystal structure of Silicon which implies that it is a single isotope (i.e 28Si) and the atomic spin is from phosphorus atoms embedded in the ZS Si crystal structure. The major point she makes is that the spin on the phosphorus nucleus and an electron (doesn't say which one of the 15 electrons) are entangled and can be used as a quantum gate (see HERE) - this is the fundamental building block - SQC are aiming to get to 100 gate computer by 2028.