title: Hyperfine structure and nuclear hyperpolarization observed in the bound exciton luminescence of Bi donors in natural Si.
abstract: As the deepest group-V donor in Si, Bi has by far the largest hyperfine interaction and also a large I = 9/2 nuclear spin. At zero field this splits the donor ground state into states having total spin 5 and 4, which are fully resolved in the photoluminescence spectrum of Bi donor bound excitons. Under a magnetic field, the 60 expected allowed transitions cannot be individually resolved, but the effects of the nuclear spin distribution, -9/2 < or = I(z) < or = 9/2, are clearly observed. A strong hyperpolarization of the nuclear spin towards I(z) = -9/2 is observed to result from the nonresonant optical excitation. This is very similar to the recently reported optical hyperpolarization of P donors observed by EPR at higher magnetic fields. We introduce a new model to explain this effect, and predict that it may be very fast.
authors.affiliation: Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
authors.forename: T
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: M
authors.initials: M
authors.lastname: Steger
authors.forename: K
authors.initials: K
authors.lastname: Saeedi
authors.forename: M L W
authors.initials: ML
authors.lastname: Thewalt
authors.forename: H
authors.initials: H
authors.lastname: Riemann
authors.forename: N V
authors.initials: NV
authors.lastname: Abrosimov
authors.forename: N
authors.initials: N
authors.lastname: Nötzel