Microscopic control of Si-29 nuclear spins near phosphorus donors in silicon

Abstract

We demonstrate an efficient control of Si-29 nuclear spins for specific lattice sites near P-31 donors in silicon at temperatures below 1 K and in a high magnetic field of 4.6 T. Excitation of the forbidden electron-nuclear transitions leads to a pattern of well-resolved holes and peaks in the electron spin resonance (ESR) lines of P-31. The pattern originates from dynamic polarization (DNP) of the Si-29 nuclear spins near the donors via the solid effect. DNP of Si-29 is demonstrated also with the Overhauser effect where the allowed ESR transitions are excited. In this case mostly the remote Si-29 nuclei having weak interaction with the donors are polarized, which results in a single hole and a sharp peak pair in the ESR spectrum. Our work shows that the solid effect can be used for initialization of Si-29 nuclear spin qubits near the donors.