Séminaire Théorie

Mardi 25 Novembre 2014 à 14h00.

From electric to thermal and thermoelectric properties of atomic and molecular junctions

''Single-atom and single-molecule junctions represent the ultimate limit to the miniaturization of electrical circuits. They are also ideal platforms for testing quantum transport theories that are required to describe charge and energy transfer in novel functional nanometer-scale devices. In this presentation, I will review the recent progress in my group towards the description of elastic and inelastic charge transport in molecular junctions as well as thermal and thermoelectric phenomena. In the first part, I will focus on the electrical properties and will discuss conductance-structure relationships [1-4] together with inelastic electron tunneling spectra [5]. In the second part, I will show recent theoretical studies of the thermopower of atomic and molecular junctions [6-10] and the connection of the thermopower to heat dissipation [11,12]. Finally, in the third and last part, I will present our recent efforts to model also the phonon transport in order to obtain a realistic figure of merit for the molecular junctions [13]. [1] F. Pauly, J. K. Viljas, U. Huniar, M. Häfner, S. Wohlthat, M. Bürkle, J. C. Cuevas, and G. Schön, New J. Phys. 10, 125019 (2008) [2] F. Pauly, J. K. Viljas, J. C. Cuevas, and G. Schön, Phys. Rev. B 77, 155312 (2008) [3] A. Mishchenko, D. Vonlanthen, V. Meded, M. Bürkle, C. Li, I. V. Pobelov, A. Bagrets, J. K. Viljas, F. Pauly, F. Evers, M. Mayor, and T. Wandlowski, Nano Lett. 10, 156 (2010) [4] M. Bürkle, J. K. Viljas, A. Mishchenko, D. Vonlanthen, G. Schön, M. Mayor, T. Wandlowski, and F. Pauly, Phys. Rev. B 85, 075417 (2012) [5] M. Bürkle, J. K. Viljas, T. J. Hellmuth, E. Scheer, F. Weigend, G. Schön, and F. Pauly, Phys. Status Solidi B 250, 2468 (2013) [6] F. Pauly, J. K. Viljas, and J. C. Cuevas, Phys. Rev. B 78, 035315 (2008) [7] M. Bürkle, L. A. Zotti, J. K. Viljas, D. Vonlanthen, A. Mishchenko, T. Wandlowski, M. Mayor, G. Schön, and F. Pauly, Phys. Rev. B 86, 115304 (2012) [8] S. Bilan, L. A. Zotti, F. Pauly, J. C. Cuevas, Phys. Rev. B 85, 205403 (2012) [9] F. Pauly, J. K. Viljas, M. Bürkle, M. Dreher, P. Nielaba, and J. C. Cuevas, Phys. Rev. B 84, 195420 (2011) [10] C. Evangeli, M. Matt, L. Rincón-García, F. Pauly, P. Nielaba, G. Rubio-Bollinger, J. C. Cuevas, and N. Agraït, submitted [11] W. Lee, K. Kim, W. Jeong, L. A. Zotti, F. Pauly, J. C. Cuevas, and P. Reddy, Nature 498, 209 (2013). [12] L. A. Zotti, M. Bürkle, F. Pauly, W. Lee, K. Kim, W. Jeong, Y. Asai, P. Reddy, and J. C. Cuevas, New J. Phys. 16, 015004 (2014) [13] F. Pauly et al., unpublished''