Experimental verification of reciprocity relations in quantum thermoelectric transport

J. MATTHEWS; F. BATTISTA; D. S ́ANCHEZ; P. SAMUELSSON

Physical Review B

APS

Año: 2014 vol. 90

Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, werepredicted two decades ago but have to date not been observed in experiments. Recent workshave predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising thequestion whether they exist in practice. Here we answer this question affirmatively by experimentallyverifying the thermoelectric reciprocity relations in a four-terminal mesoscopic device where eachterminal can be electrically and thermally biased, individually. The linear response thermoelectriccoefficients are found to be symmetric under simultaneous reversal of magnetic field and exchangeof injection and emission contacts. We also demonstrate a controllable breakdown of the reciprocityrelations by increasing thermal bias, putting in prospect enhanced thermoelectric performance.