Thermoelectric energy harvesters can help to recover waste heat, e.g., on a computer chip 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].

Bibliography:
[1] R. Sánchez and M. Büttiker, PRB 83, 085428 (2011).
[2] B. Sothmann, R. Sánchez, A. N. Jordan and M. Büttiker, PRB 85, 205301 (2012).
[3] A. N. Jordan, B. Sothmann, R. Sánchez and M. Büttiker, PRB 87, 075312 (2013).
[4] B. Sothmann and M. Büttiker, EPL 99, 27001 (2012).
[5] C. Bergenfeldt, P. Samuelsson, B. Sothmann, C. Flindt and M. Büttiker, PRL 112, 076803 (2013).