Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 9: Poster I
HL 9.74: Poster
Montag, 27. März 2006, 15:15–17:45, P3
Coherent single electron spins manipulation in a quantum dot — •Dawid Kupidura, Stefan Ludwig, and Jörg Kotthaus — Department für Physik der LMU München, Lehrstuhl Prof. Kotthaus, Geschwister-Scholl-Platz 1, 80539 München
Recent progress in solid state quantum dots allowed measurement of the energy relaxation times as well as the phase coherence times of charge and spin qubits. Maybe the most impressive experiment employs the singlet-triplet splitting in a two-electron double quantum dot [1]. The latter measurements indicate the coherence time T2 > 1.2 µs [1]. This time may be limited due to the Overhauser magnetic field (caused by hyperfine interactions) varying in space and in time. Another origin of decoherence in this experiment might be electrostatic potential fluctuations in time that modify the exchange interaction [1].
In our approach we plan to use the two Zeeman-split spin states of an electron in a single quantum dot as originally proposed by Loss and DiVincenzo [2]. An advantage of this design is its robustness against local potential fluctuations as well as against the fluctuating Overhauser field (Bext >> Bnuclear). We aim towards a single electron spin resonance experiment by additionally to Bext applying a pulsed RF-magnetic field. Single spin read-out for such an experiment was demonstrated elsewhere [3].
[1] J. R. Petta et. al. Science 309, 2180 (2004) [2] D. Loss and D. P. DiVincenzo PRA 57, 120 (1998) [3] J. M. Elzerman et. al. Nature 430, 431 (2004)