A08 – Vibrational properties and phonon transport of nanobridges

Funding period: 01/2016 – 12/2019

Principal investigator: Fabian Pauly

Scientific staff: Jan C. Klöckner, Maxim Skripnik

We will study how vibrational properties of nanobridges can be tuned through temperature and mechanical stress. Developing an ab-initio description based on density functional theory, we will include anharmonic effects to consider their influence on the heat current by phonons and its fluctuations. Within this methodology that allows to determine phonon lifetimes based on phonon-phonon scattering, we will focus on molecular and atomic scale junctions. We will explore the dependence of phonon transport on molecular shape, conjugation, anchoring groups, substituents and electrode materials as well as ways to achieve a suppression of thermal conductance through destructive phonon interference and increased anharmonicities. Finally, using molecular dynamics and force fields, calibrated with the ab-initio approach, we will explore a new type of thermal diode that exploits different thermal expansion coefficients to achieve a high rectification ratio.

The transmission as a function of energy. The three arrows mark the specific transmission modes of the C60 gold contacts, animated in the previous videos.

For further information please also refer to the group website: AG Pauly

List of publications

2019

  •  J. C. Klöckner and F. Pauly
    Variability of the thermal conductance of gold-alkane-gold single-molecule junctions studied using ab-initio and molecular dynamics approaches
    arXiv:1910.02443
  • L. Cui, S. Hur, Z. A. Akbar, J. C. Klöckner, W. Jeong, F. Pauly, S.-Y. Jang, P. Reddy, and E. Meyhofer
    Thermal conductance of single-molecule junctions
    Nature 572, 628–633 (2019) - DOI: 10.1038/s41586-019-1420-z
    Press Release UKON: Heat transport through single molecules
  • D. O. Möhrle, F. Müller, M. Matt, P. Nielaba, and F. Pauly
    Statistical analysis of electronic and phononic transport simulations of metallic atomic contacts
    Phys. Rev. B 100, 125433 (2019) - DOI: 10.1103/PhysRevB.100.125433

2018

  • J. C. Klöckner, J. C. Cuevas, and F. Pauly
    Transmission eigenchannels for coherent phonon transport
    Phys. Rev. B 97, 155432 (2018) - DOI: 10.1103/PhysRevB.97.155432

2017

  • J. C. Klöckner, J. C. Cuevas, and F. Pauly
    Tuning the thermal conductance of molecular junctions with interference effects
    Phys. Rev. B 96, 245419 (2017) - DOI: 10.1103/PhysRevB.96.245419
  •  J. C. Klöckner, M. Matt, P. Nielaba, F. Pauly, and J. C. Cuevas
    Thermal conductance of metallic atomic-size contacts: phonon transport and Wiedemann-Franz law
    Phys. Rev. B 96, 205405 (2017) - DOI: 10.1103/PhysRevB.96.205405
  •  J. C. Klöckner, R. Siebler, J. C. Cuevas, and F. Pauly
    Thermal conductance and thermoelectric figure of merit of C60-based single-molecule junctions: Electrons, phonons, and photons
    Phys. Rev. B 95, 245404 (2017) - DOI: 10.1103/PhysRevB.95.245404
  • L. Cui, W. Jeong, S. Hur, M. Matt, J. C. Klöckner, F. Pauly, P. Nielaba, J. C. Cuevas, E. Meyhofer, and P. Reddy
    Quantized thermal transport in single-atom junctions 
    Science 355, 1192 (2017) - DOI: 10.1126/science.aam6622
    Press release of the UKON in English and German
    Explanatory video

Popular science 2017

  • M. Matt, J. C. Klöckner, F. Pauly and P. Nielaba
    Wärmefluss durch einzelne Atome
    Phys. Unserer Zeit 48, 110 (2017) - DOI:  10.1002/piuz.201770304

2016

  • J. C. Klöckner, M. Bürkle, J. C. Cuevas, and F. Pauly
    Length dependence of the thermal conductance of alkane-based single-molecule junctions: An ab-initio study
    Phys. Rev. B 94, 205425 (2016) - DOI:  10.1103/PhysRevB.94.205425