Quantum dots are another type of artificial atom which can be realized in semiconductors. Such dots form naturally e.g. when thin layers of InGaAs are grown on GaAs. Self-organized quantum dots are already used commercially in light emitting diodes, but are still subject to intense investigations of their fundamental physical properties. One interesting aspect is the fact that single electrons or holes can be stored in these quantum dots for very long times. Using circularly polarized light for the excitation of the quantum dot, the electron or hole can be created with a specific spin state which, notably, also survives for hundreds of microseconds. For the application of these spin states in quantum information processing, also their decoherence has to be slow compared to the clock rate of future processors. We study the spin decoherence in quantum dots using pulsed magnetic resonance techniques and develop new methods to efficiently read out the spin state of single charge carriers in quantum dots.
Observation of extremely slow hole spin relaxation in self-assembled quantum dots
Physical Review B 76, 241306 (2007)
D. Heiss, S. Schaeck, H. Huebl, M. Bichler, G. Abstreiter, J. J. Finley, D. V. Bulaev, D. Loss
Spintronics: Information Processing with Spins
WSI Book (2008) Download