First-principles investigation of hyperfine interactions for nuclear spin entanglement in photoexcited fullerenes
Phys. Rev. B 85, 115430 – Published 22 March, 2012
DOI: https://doi.org/10.1103/PhysRevB.85.115430
Abstract
The study of hyperfine interactions in optically excited fullerenes has recently acquired importance within the context of nuclear spin entanglement for quantum-information technology. We here report a first-principles pseudopotential study of the hyperfine coupling parameters of optically excited fullerene derivatives as well as small organic radicals. The calculations are performed within the gauge-invariant projector-augmented wave method [C. Pickard and F. Mauri, Phys. Rev. B 63, 245101 (2001)]. In order to establish the accuracy of this methodology we compare our results with all-electron calculations and with experiment. In the case of fullerene derivatives we study the hyperfine coupling in the spin-triplet exciton state and compare our calculations with recent electron paramagnetic resonance measurements [M. Schaffry et al., Phys. Rev. Lett. 104, 200501 (2010)]. We discuss our results in light of a recent proposal for entangling remote nuclear spins in photoexcited chromophores.