Tunable spin Seebeck effect in a double Rashba molecule embedded in an Aharonov–Bohm interferometer

•We study spin thermoelectric properties of a Rashba molecule in an interferometer.•The spin Seebeck effect can be tuned by the Aharonov–Bohm and Rashba induced phases.•This effect is accompanied by significant values of spin the figures of merits.

We study the spin-dependent thermoelectric properties of a Rashba quantum dot-molecule embedded in an Aharonov–Bohm interferometer. We show that by tuning conveniently both the Aharonov–Bohm and the Rashba spin orbit-induced phases, the different components of spin can have Seebeck coefficients of equal magnitude and different signs, so that the charge Seebeck coefficient vanishes while the spin Seebeck coefficient is finite. This means that a temperature gradient can produce in this system a spin voltage at the time that the charge voltage is zero, occurring an equivalent to the spin Seebeck effect observed in ferromagnets.