In metallic structures at very low temperatures heat and energy are carried mostly by electrons. When these structures are small, with dimensions of the order of nanometers, many kinds of quantum phenomena become significant. The combination of heat transport with these effects, with a special focus on the random fluctuations of temperature in these systems, is the topic of this Dissertation. Using quantum transport theory, we have studied the flow of heat and charge in some prototypical nanoelectronic systems, e.g., single-electron transistor and superconductor-normal metal tunnel structure. We have devised a powerful theoretical method for the calculation of probability distributions of fluctuating quantities, especially temperature, and used it to find cases where the statistics of these fluctuations becomes non-Gaussian. We have also shown how the fluctuations of temperature affect the fluctuations of the electric current. In some cases the temperature-fluctuation induced current noise can be orders of magnitude larger than the intrinsic shot noise of the system. We also address the possibility to detect these fluctuations by monitoring the induced current noise.
|Translated title of the contribution||Lämpötilan satunnaisvaihtelut ja lämmönkuljetus nanoelektroniikan rakenteissa|
|Publication status||Published - 2012|
|MoE publication type||G5 Doctoral dissertation (article)|
- temperature fluctuations
- heat transport