Berlin 2015 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 41: Spintronics: Excitons and Local Spins (jointly with HL, MA)
TT 41.6: Talk
Tuesday, March 17, 2015, 10:45–11:00, ER 270
Spin Dynamic of Electrons and Holes in Single Quantum Dots — •Ramin Dahbashi1, Julia Wiegand1, Jens Hübner1, Klaus Pierz2, Arne Ludwig3, Andreas Wieck3, and Michael Oestreich1 — 1Leibniz Universität Hannover, Institut für Festkörperphysik, Abteilung Nanostrukturen, Appelstr. 2, D-30167 Hannover, Germany — 2Physikalisch Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany — 3Ruhr-Universität Bochum, Angewandte Festkörperphysik, Universitätsstr. 150, D-44801 Bochum, Germany
We present new insights into single quantum dot (QD) spin noise spectroscopy (SNS) [1]. We have performed world’s first measurements of the single heavy hole spin dynamic in an individual (InGa)As QD by SNS [2]. These measurements reveal (a) very long T1 hole spin lifetimes of up to 180 µs even in the low magnetic field range of up to 30 mT as well as (b) charge fluctuations in the QD surrounding. In order to suppress the parasitic influence of charge fluctuations, we move to QDs embedded in a Schottky diode structure which yields three main advantages: (i) the charge state of the QD, i.e., electron or hole, can be changed facilitating different coupling strength to the nuclear spin bath, (ii) the sharp single QD resonance can be tuned via the quantum confined Stark shift, and (iii) charge fluctuations are strongly reduced.
[1] J. Hübner, F. Berski, R. Dahbashi, and M. Oestreich, physica status solidi (b) 251, 1824 (2014).
[2] R. Dahbashi, J. Hübner, F. Berski, K. Pierz, and M. Oestreich, Phys. Rev. Lett 112, 156601 (2014).