Origin of vibrational instabilities in molecular wires with separated electronic states

0490401 - FZÚ 2019 RIV US eng J - Journal Article
Foti, Giuseppe - Vázquez, Héctor
Origin of vibrational instabilities in molecular wires with separated electronic states.
Journal of Physical Chemistry Letters. Roč. 9, č. 11 (2018), s. 2791-2796. ISSN 1948-7185
R&D Projects: GA ČR GA15-19672S
EU Projects: European Commission(XE) 709114 - HEATEXMOL
Institutional support: RVO:68378271
Keywords : current-induced heating * electronic excitation * first-principles calculation
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 7.329, year: 2018

Current-induced heating in molecular junctions stems from the interaction between tunneling electrons and localized molecular vibrations. If the electronic excitation of a given vibrational mode exceeds heat dissipation, a situation known as vibrational instability is established, which can seriously compromise the integrity of the junction. Using out of equilibrium first-principles calculations, we demonstrate that vibrational instabilities can take place in the general case of molecular wires with separated unoccupied electronic states. From the ab initio results, we derive a model to characterize unstable vibrational modes and construct a diagram that maps mode stability. These results generalize previous theoretical work and predict vibrational instabilities in a new regime.
Permanent Link: http://hdl.handle.net/11104/0284642