Dresden 2020 – scientific programme

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O: Fachverband Oberflächenphysik

O 106: Frontiers in Electronic-Structure Theory - Focus on Electron-Phonon Interactions V (joint session O/CPP/DS/HL)

O 106.8: Talk

Thursday, March 19, 2020, 17:00–17:15, GER 38

How Electric Fields Affect Intermolecular van der Waals Interactions — •Mohammad Reza Karimpour, Dmitry Fedorov, and Alexandre Tkatchenko — University of Luxembourg, 1511 Luxembourg, Luxembourg

van der Waals (vdW) dispersion interactions between atoms or molecules originate from electromagnetic forces caused by the zero-point quantum-mechanical fluctuations of electronic charge densities. They are ubiquitous in nature and present in many areas of physics, chemistry, biology, and nanotechnology. Recently, it has been shown that the strength of vdW interactions can be controlled and tailored by external electric charges [1]. In addition, an external field strongly modifies the dispersion interaction between two hydrogen atoms and can change both its spatial dependence and its attractive or repulsive character [2]. To describe such important phenomena in large molecular systems, we employ the Many-Body Dispersion (MBD) method [3] based on the quantum Drude oscillator model. Since the conventional MBD method includes only dipole-dipole coupling, it does not capture the effects of external fields on vdW interactions. Therefore, we first extend the approach to dipole-quadrupole and quadrupole-quadrupole couplings. Then, the developed formalism is applied to calculate the MBD energy in the presence of an external electric field for low-dimensional systems including bilayer graphene.

[1] Kleshchonok and Tkatchenko, Nat. Commun. 9, 3017 (2018)

[2] Fiscelli et al. arXiv:1909.03517 (2019)

[3] Tkatchenko et al. Phys. Rev. Lett. 108, 236402 (2012)