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O: Fachverband Oberflächenphysik
O 2: Focus Session: Frontiers of Electronic-Structure Theory – Advances in Time-Dependent and Nonequilibrium Ab Initio Methods I
O 2.10: Vortrag
Montag, 18. März 2024, 12:45–13:00, HE 101
Path-integral generalized Langevin dynamics: quantum nuclei with position-dependent friction — •George Trenins1, Paolo Lazzaroni1, Yair Litman2, and Mariana Rossi1 — 1MPI for the Structure and Dynamics of Matter, Hamburg, Germany — 2Yusuf Hamied Department of Chemistry, University of Cambridge, UK
Dissipative dynamics model large-scale problems by treating a few degrees of freedom explicitly and describing the rest statistically. For example, in the study of nuclear dynamics at metal interfaces, nonadiabatic coupling to the electrons can be modelled as “electronic friction” [1]. Such systems with no clear separation of timescales are a computational challenge, due to the dependence of the dissipative forces on position and time. To address this, our group has developed an instanton rate theory that accounts both for the friction and for nuclear quantum effects [2]. However, since this theory cannot describe reactions taking place in liquid environments, we explore an alternative approach, explicitly introducing friction into ring-polymer molecular dynamics [3]. This framework uncovers the unexpected interplay between position-dependent friction and quantum dynamics in a model potential. We show practical approaches to propagating the underlying equations of motion and solutions to simulating multidimensional quantum dissipative systems. [1] W. Dou, J. E. Subotnik, JCP 148, 230901 (2018). [2] Y. Litman et al. JCP 156, 194106 (2022). [3] S. Habershon et al. Annu. Rev. Phys. Chem. 64, 387–413 (2013).
Keywords: path integrals; electronic friction; instantons; rate theory; open quantum system