Thermoelectric effects in molecular quantum dots with contacts

0432315 - FZÚ 2015 RIV US eng J - Článek v odborném periodiku
Koch, T. - Loos, Jan - Fehske, H.
Thermoelectric effects in molecular quantum dots with contacts.
Physical Review. B. Roč. 89, č. 15 (2014), "155133-1"-"155133-11". ISSN 1098-0121
Institucionální podpora: RVO:68378271
Klíčová slova: theory of electronic transport * scattering mechanisms * polarons and electron-phonon interactions * quantum dots
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.736, rok: 2014

We consider the steady-state thermoelectric transport through a vibrating molecular quantum dot that is contacted to macroscopic leads. For moderate electron-phonon interaction strength and comparable electronic and phononic timescales, we investigate the impact of the formation of a local polaron on the thermoelectric properties of the junction. We apply a variational Lang-Firsov transformation and solve the equations of motion in the Kadanoff-Baym formalism up to second order in the dot-lead coupling parameter. We calculate the thermoelectric current and voltage for finite temperature differences in the resonant and inelastic tunneling regimes. For a near resonant dot level, the formation of a local polaron can boost the thermoelectric effect because of the Franck-Condon blockade. The line shape of the thermoelectric voltage signal becomes asymmetrical due to the varying polaronic character of the dot state and in the nonlinear transport regime, vibrational signatures arise.
Trvalý link: http://hdl.handle.net/11104/0236723