"From electric to thermoelectric transport properties of atomic and molecular junctions" Prof. Fabian Pauly

Dr. Fabian Pauly

Junior Professor

Department of Physics

University of Konstanz, Germany

Abstract

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 seminar, I will review the recent theoretical progress of my group towards the description of elastic and inelastic charge transport in atomic and molecular junctions as well as thermoelectric phenomena. After a brief introduction to the field of molecular electronics, I will discuss results on the influence of conjugation on conductance [1,2], inelastic electron tunneling spectra [3,4] and the thermopower [5-8]. Next, I will present combined experimental and theoretical efforts to understand the heat dissipation in atomic-scale junctions [9]. Furthermore, I will show an ab-initio characterization of the thermoelectric figure of merit of molecular junctions including both electronic and phononic contributions to the thermal conductance [10]. In the end, I will discuss ongoing research projects as well as perspectives.

1. Influence of conformation on conductance of biphenyl-dithiol single-molecule contacts, 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)
2. Conduction mechanisms in biphenyl-dithiol single-molecule junctions, M. Bürkle, J. K. Viljas, A. Mishchenko, D. Vonlanthen, G. Schön, M. Mayor, T. Wandlowski, and F. Pauly, Phys. Rev. B 85, 075417 (2012)
3. Influence of vibrations on electron transport through nanoscale contacts, M. Bürkle, J. K. Viljas, T. J. Hellmuth, E. Scheer, F. Weigend, G. Schön, F. Pauly, Phys. Status Solidi B 250, 2468 (2013)
4. Identification of the current path for a conductive molecular wire on a tripodal platform, M. A. Karimi, S. G. Bahoosh, M. Valášek, M. Bürkle, M. Mayor, F. Pauly, and E. Scheer (submitted)
5. Ab initio study of the thermopower of biphenyl-based single-molecule junctions, M. Bürkle, L. A. Zotti, J. K. Viljas, D. Vonlanthen, A. Mishchenko, T. Wandlowski, M. Mayor, G. Schön, F. Pauly, Phys. Rev. B 86, 115304 (2012)
6. Length-dependent conductance and thermopower in single-molecule junctions of dithiolated oligophenylene derivatives, F. Pauly, J. K. Viljas, and J. C. Cuevas, Phys. Rev. B 78, 035315 (2008)
7. Molecular dynamics study of the thermopower of Ag, Au, and Pt nanocontacts, F. Pauly, J. K. Viljas, M. Bürkle, M. Dreher, P. Nielaba, J. C. Cuevas, Phys. Rev. B 84, 195420 (2011)
8. Quantum thermopower of metallic atomic-size contacts at room temperature, C. Evangeli, M. Matt, L. Rincón-García, F. Pauly, P. Nielaba, G. Rubio-Bollinger, J. C. Cuevas, N. Agraït, Nano Lett. 15, 1006 (2015)
9. Heat dissipation in atomic-scale junctions, W. Lee, K. Kim, W. Jeong, L. A. Zotti, F. Pauly, J. C. Cuevas, P. Reddy, Nature 498, 209 (2013)
10. First principles calculation of the thermoelectric figure of merit for [2,2]paracyclophane-based single-molecule junctions, M. Bürkle, T. J. Hellmuth, F. Pauly, Y. Asai, Phys. Rev. B 91, 165419 (2015)

Biography

Fabian Pauly obtained his PhD at University of Karlsruhe in 2007 in the group of Prof. Gerd Schön at the Institute for Theoretical Solid State Physics. His thesis was entitled “Phase-coherent electron transport through metallic atomic-sized contacts and organic molecules”. The University of Karlsruhe renamed itself to Karlsruhe Institute of Technology (KIT) in 2008. Immediately after his PhD, Fabian Pauly was awarded a “Young Investigator Group” by the “Council for Research and Promotion of Young Scientists” within the Excellence Initiative at KIT entitled “Theoretical Aspects of Molecular Electronics”. After a period of 4 years as an independent research group leader, he went as a postdoc to the Materials Sciences Division to work with Prof. J. B. Neaton at the Lawrence Berkeley National Laboratory, USA. Since 2012 he holds a Junior Professorship at University of Karlsruhe, heading the group “Theory of Nanostructures”.