The efficient use of available energy sources is of increasing importance. Energy harvesters that convert energy from the environment into useful work can help to accomplish this task. One particular class of energy harvesters consists of thermoelectric materials that convert waste heat back into electricity. Despite decades of material research the progress towards efficient thermoelectric materials is slow. Mesoscopic solid-state physics may help to overcome the limitations of current thermoelectric devices.
Here, we present recent efforts to find powerful and efficient energy harvesters based on Coulomb-coupled quantum dots in a three-terminal geometry. The latter offers the advantage of separating hot and cold reservoirs and having crossed flows of heat and charge currents. We analyze systems based on quantum dots in the Coulomb-blockade regime [1], chaotic cavities [2] and resonant-tunneling quantum dots [3]. Finally, we also discuss quantum-dot heat engines operated by magnons [4] and microwave cavity photons [5].
