Heat engines are an integral part of our daily lives. They power cars or produce electricity by converting heat into work. Increasing their efficiency is very difficult and only marginal improvements have been achieved over the last decades. Thus, to reach the ambitious climate goals, it is necessary to go beyond conventional technologies. Atom-sized systems where quantum mechanical effects come into play could enable this: theory predicts that their efficiency can be boosted beyond the classical limits imposed by thermodynamics. However, so far, this has not been tested in practice due to a lack of suitable model systems.
In this project, I propose to build a molecular heat engine of only a few atoms in size, with such high control over its structure and properties that these predictions can finally be tested. The engine’s quantum properties will be robust at experimentally accessible temperatures, its coupling to the environment will be controllable, and electrical transport through it will be quantum coherent. I seek to exploit the full gamut of their physical properties to boost efficiency, including spin entropy and vibrational coupling.
The fundamental insight obtained in MOUNTAIN will have huge impact on our understanding of heat and particle flow at the atomic limit. Furthermore, we will reveal experimentally the fundamental, quantum thermodynamic efficiency limits of a quantum heat engine, which will be highly relevant for the nanoscopic and quantum physics community and will fuel future theoretical and experimental work in the fields of non-equilibrium quantum systems, molecular electronics and thermoelectric devices. Although MOUNTAIN focusses on the fundamental aspects of molecular quantum heat engines, the obtained results will define the limits and possibilities for engineering future thermoelectric applications like energy harvesters of waste heat, highly efficient (cryogenic) nanoscale spot-cooling devices for thermal management applications, thermal rectifiers and transistors or even thermal logic gates and memory.
