Regensburg 2004 – wissenschaftliches Programm
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SYSN: Quantum Shot Noise in Nanostructures
SYSN 2: Quantum Shot Noise in Nanostructures
SYSN 2.3: Vortrag
Montag, 8. März 2004, 17:00–17:15, H1
Shot noise in resonant single electron tunneling through InAs quantum dots — •Frank Hohls1, André Nauen1, Niels Maire1, Rolf Haug1, and Klaus Pierz2 — 1Institut für Festkörperphysik, Universität Hannover, D-30167 — 2Physikalisch-Technische Bundesanstalt, Bundesallee 100,
We investigate the noise properties of resonant single electron transport through self-assembled InAs quantum dots which are embedded in the AlAs barrier of a GaAs-AlAs-GaAs tunneling device. Due to their small size (diameter 10-15 nm and height 3 nm) these quantum dots display both strong size quantization and Coulomb blockade. Thus the tunneling current through our device is given by resonant single electron tunneling through the ground state of the quantum dot.
The measured noise spectrum of the current is dominated by frequency-independent shot noise for frequencies above 1 kHz. As expected for single electron tunneling the spectral noise power S is suppressed in comparison to the full Poissonian shot noise 2eI observed for single barrier tunneling. We observe a linear voltage dependence of the suppression α=S/2eI which can be related to the dimensionality of the source contacts. At the onset of the resonant current we observe additional features which are probably caused by a correlation effect between dot and lead known as fermi edge singularity.