TY - JOUR
T1 - Thermopower of single-molecule devices
AU - Koch, Jens
AU - Von Oppen, Felix
AU - Oreg, Yuval
AU - Sela, Eran
N1 - Funding Information:
The authors thank I. Bar-Joseph for suggesting an investigation of thermoelectric effects in single-molecule devices and C. Timm for useful discussions. Two of the authors (F.v.O. and J.K.) thank the Weizmann Institute for hospitality (supported through the LSF and the Einstein Center). This work was supported in part by SFB 290, the Junge Akademie (F.v.O.), as well as the Minerva Foundation, and DIP under Grant No. C-7.1 (Y.O.).
PY - 2004/11
Y1 - 2004/11
N2 - We investigate the thermopower of single molecules weakly coupled to metallic leads. We model the molecule in terms of the relevant electronic orbitals coupled to phonons corresponding to both internal vibrations and to oscillations of the molecule as a whole. The thermopower is computed by means of rate equations including both sequential-tunneling and cotunneling processes. Under certain conditions, the thermopower allows one to access the electronic and phononic excitation spectrum of the molecule in a linear-response measurement. In particular, we find that the phonon features are more pronounced for weak lead-molecule coupling. This way of measuring the excitation spectrum is less invasive than the more conventional current-voltage characteristic, which, by contrast, probes the system far from equilibrium.
AB - We investigate the thermopower of single molecules weakly coupled to metallic leads. We model the molecule in terms of the relevant electronic orbitals coupled to phonons corresponding to both internal vibrations and to oscillations of the molecule as a whole. The thermopower is computed by means of rate equations including both sequential-tunneling and cotunneling processes. Under certain conditions, the thermopower allows one to access the electronic and phononic excitation spectrum of the molecule in a linear-response measurement. In particular, we find that the phonon features are more pronounced for weak lead-molecule coupling. This way of measuring the excitation spectrum is less invasive than the more conventional current-voltage characteristic, which, by contrast, probes the system far from equilibrium.
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U2 - 10.1103/PhysRevB.70.195107
DO - 10.1103/PhysRevB.70.195107
M3 - Article
AN - SCOPUS:12444286752
SN - 1098-0121
VL - 70
SP - 1
EP - 12
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 19
M1 - 195107
ER -