Seminarium "Coherence-Correlations-Complexity" (KFT, PWr)

Statistics of current fluctuations in quantum dot systems

Krzysztof Ptaszyński

Instytut Fizyki Molekularnej PAN

Current single electron counting techniques, allowing measurements of very low currents, enable also to determine statistical distributions of current fluctuations resulting from the charge quantization (i.e. shot noise). Study of such fluctuations can provide important information about the transport mechanism, e.g. about inter-electron interactions or coupling with external spin or vibrational degrees of freedom. Seminary focuses on the analysis of distributions of waiting times between subsequent tunneling events. It shows, that the waiting time distribution can give information about internal spin dynamics of the quantum dot molecule attached to spin-polarized leads, which is not provided by the more common full counting statistics approach. I also present physical mechanisms generating both positive and negative correlations of subsequent waiting times and show that such correlations can be detected by measuring the second-order current correlation function.