Carbon Nanotube quantum dots: Transport, mechanical charge detection, and fabrication development

Within this thesis, a diverse set of experiments on carbon nanotube quantum dots is presented and evaluated. Different fabrication methods, and improvement of single steps of established known procedures are used to obtain suspended CNT devices. In particular, an ultraclean carbon nanotube quantum dot is examined regarding low-temperature transport. Furthermore, its outstanding nano-electromechanical properties are used to infer the charge distribution in the Kondo regime. Theoretical calculations from previous work are extended to model the CNT quantum dot as nano-electromechanical system. Applying these results to the measured data, a characteristic shift is attributed to the Kondo effect. The second part of this thesis deals with optimization of molybdenum rhenium alloys for CNT contact materials. This alloy is the third material besides platinum and pristine rhenium at all to withstand carbon nanotube growth conditions. In addition, low-temperature transport measurements of CNTs suspended in between MoRe electrodes are presented and evaluated. In order to circumvent the restriction of suitable contact materials for the overgrowth technique, another fabrication approach was performed. The main objective was to prove that carbon nanotubes can be stamped onto arbitrary target chips. At the end of this work, the stamping approach for carbon nanotube devices delivers first low-temperature transport results of our group