In an electronic circuit, current can be generated by the conversion of heat absorbed from a hot region. In the absence of a magnetic field, such thermoelectric response requires broken left-right and particle- hole symmetries. We investigate the thermoelectric properties of a three-terminal quantum Hall conductor. We identify a contribution to the thermoelectric response that relies on the chirality of the carrier motion rather than on spatial asymmetries [1]. The Onsager matrix becomes maximally asymmetric with configurations where either the Seebeck or the Peltier coefficients are zero while the other one remains finite. Reversing the magnetic field direction exchanges these effects. Our results show that thermoelectric measurements are sensitive to the chiral nature of the quantum Hall edge states, opening the way to control quantum coherent heat flows. In particular, powerful and efficient energy harvesters can be proposed [1,2]. The possibility to generate spin-polarized currents in quantum spin Hall samples is also discussed.

Bibliography:
[1] R. Sánchez, A. N. Jordan, B. Sothmann, arXiv:1410.6639
[2] B. Sothmann, R. Sánchez, A. N. Jordan, Europhys. Lett. 107 47003 (2014).