Hannover 2013 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 35: Poster I
Q 35.48: Poster
Dienstag, 19. März 2013, 16:00–18:30, Empore Lichthof
Electron spin decoherence of divacancy defect center in silicon carbide nuclear spin baths — •Christian Burk1, Julia Michl1, Nan Zhao2, and Jörg Wrachtrup1 — 13. Physikalisches Institut, Universität Stuttgart, 70550 Stuttgart, Germany — 2Beijing Computational Science Research Center, Beijing 100084, China
The neutral divacancy in silicon carbide is a defect center which can be controlled coherently. It is very similar to the well-known nitrogen-vacancy center in diamond, as it is also a paramagnetic defect center in a solid with a spin S = 1 ground state, and can be polarized via excitation into an excited state and an alternate decay path over a metastable singlet state, which also allows for optical readout. Thus it is a promising system for quantum information processing or as a magnetic probe for sensing. Since the defect center is embedded in a lattice consisting of carbon and silicon atoms, there can be stable spin bearing isotopes of these atoms. Those isotopes (13C and 29Si, both with spin S=1/2) act as a source of decoherence. Since there are too many relevant interactions between the divacancy and the nuclear spins and the nuclear spins with each other to completely include them all in calculations, the nuclear spins are generally treated as an environment or more specifically as a nuclear spin bath for the central electron spin. To effectively manipulate a defect center, the effects that occur due to the interaction with its environment have to be understood. To overcome the limitation, that prevents a purely quantum mechanical treatment of the bath due to its size, a cluster correlation expansion for this system was applied.