Title: Single Molecule Electron Transport and Current-induced Heating Within DFT.
When: Monday, September 16, (2019), 12:00.
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor).
Speaker: Hector Vázquez, Molecular Transport group Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Single molecule circuits, in which an electrical current is passed through individual molecules, represent a playground for investigating a series of quantum phenomena. To correctly understand and predict current-induced behaviour, a detailed description of the metal-molecule-metal electronic structure is needed. DFT-based approaches provide accuracy and transferability although at a high computational cost.
Of particular interest are interactions between electronic and vibrational degrees of freedom. When a bias voltage is applied, energy exchanged between electrons and localized vibrations, which result in peaks in the second derivative of the current with respect to the voltage. The talk will discuss our work in characterizing these interactions and mapping their spatial origin inside the junction [1,2]. In addition, this energy exchange between electrons vibrations can heat, but also cool, the molecular junction, and can affect the stability of molecular circuit if heating processes are not balanced [3].
References
G. Foti and H. Vázquez, Phys. Rev. B 94 045418 (2016).
B. de la Torre, M. Švec, G. Foti, O. Krejči, P. Hapala, A. García-Lekue, T. Frederiksen, R. Zbořil, A. Arnau, H. Vázquez and P. Jelínek, Phys. Rev. Lett. 119 166001 (2017).
G. Foti and H. Vázquez, J. Phys. Chem. Lett. 9 2791 (2018).