Regensburg 2007 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 18: Nanoelectronics I - Quantum Dots, Wires, Point Contacts

TT 18.3: Talk

Wednesday, March 28, 2007, 14:30–14:45, H19

Frequency dependent quantum shot noise — •Jan C. Hammer and Wolfgang Belzig — University of Konstanz, Department of Physics, 78457 Konstanz, Germany

We study frequency-dependent quantum shot noise in the coherent charge transport through a double barrier quantum dot. In the framework of the scattering formalism we show how electron transport through such a Fabry-Perot-like setup reveals a super-Poissonian and an asymmetric noise spectrum for large frequencies. It depends on the applied bias voltage, the structure of the energy levels inside the scattering region and the coupling to the leads. For example, well separated energy levels lead to steps in the noise due to the emission and absorption of photons which get washed out as the width of the levels broadens. These can be shifted with respect to frequency by varying a gate voltage. At low frequency the Fano factor gets reduced and the spectrum is found to be symmetric.