Regensburg 2022 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 15: Nano- and Optomechanics

TT 15.2: Talk

Tuesday, September 6, 2022, 11:30–11:45, H23

Current-induced forces in nano-electromechanical systems: A hierarchical equations of motion approach — •Samuel Rudge and Michael Thoss — Physikalisches Institut, Albert-Ludwigs Universität Freiburg

Current-induced forces in nanostructures provide valuable insight into the mechanisms of nonequilibrium charge transport through nano-electromechanical systems [1]. In this contribution, we investigate specifically the electronic friction in molecular junctions using the hierarchical equations of motion approach [2-3]. Since this method is, in principle, numerically exact, it allows us to extend previous studies [4] beyond the Born-Markov approximation and incorporate strong intra-system interactions. To demonstrate the approach, we consider a resonant level model coupled to a low-frequency vibrational mode, which is treated semi-classically, and reproduce the exact electronic friction known from nonequilibrium Green’s function theory [4]. We then also incorporate a high-frequency vibrational mode, which is strongly coupled to the electronic degrees of freedom and is treated fully quantum mechanically.

[1] J. T. Lü et al., Phys. Rev. B 85, 245444 (2012)

[2] Y. Tanimura, J. Chem. Phys. 153, 020901 (2020)

[3] J. Bätge et al., Phys. Rev. B 103, 235413 (2021)

[4] W. Dou et al., J. Chem. Phys. 143 054103 (2015)