Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 89: Focus Session: Quantum Information Systems (jointly with MA,TT)

HL 89.4: Vortrag

Donnerstag, 29. März 2012, 17:30–17:45, ER 164

Spin decoherence in graphene quantum dots due to hyperfine interaction — •Moritz Fuchs, Valentin Rychkov, and Björn Trauzettel — Institut für Theoretische Physik und Astrophysik, University of Würzburg, 97074 Würzburg, Germany

Carbon based systems are prominent candidates for a solid-state spin-qubit due to weak spin-orbit and hyperfine interactions in combination with a low natural abundance of spin carrying isotopes. We consider the effect of the hyperfine interaction on the coherence of an electron-spin localized at gate-defined graphene quantum dots. It is known, that the hyperfine interaction in these systems is anisotropic promising interesting physics. We calculate the dynamics of an electron spin surrounded by a bath of nuclear spins in a non-Markovian approach, where we find, that the electron spin state is conserved up to small corrections. These corrections, however, show an intriguing interplay of power-law and exponential decaying behavior depending on the orientation of an external magnetic field.