Beyond the Born-Oppenheimer approximation:
from water superlow in carbon nanotubes, to long-range
electron-nuclear coupling in photoactive proteins
Abstract:
In The Born-Oppenheimer (BO) approximation is a powerful and broadly adopted framework, which effectively separates fast electronic degrees of freedom from slow ionic coordinates. While the advantages BO approach are self-evident in electronic structure theories, the main drawback is a classicization of nuclei, which can hide emergent quantum mechanical effects. Here two unexpected beyond-BO quantum mechanisms will be illustrated: i) The first is a quantum mechanical suppression of friction forces for He or water molecules flowing
through narrow carbon nanotubes. This mechanism presents close analogies to superfluidity, and consents virtually non-dissipative mass transport at the nanoscale. ii)The second effect is a highly non-local diabatic coupling between exciton pairs and vibrational modes in photoactive proteins. This coupling mechanism – active in the UV frequency regime- is mediated by van der Waals interactions and enables efficient energy transfer between aromatic amino-acids at distance. Such a coupling provides an efficient alternative to Foerster resonance energy transfer (FRET), and could be exploited by proteins as a self-defence mechanism, by which the energy of potentially dangerous UV photons can be rapidly redistributed through the entire structure.
About the speaker:
Alberto Ambrosetti is currently an Assistant Professor at the University of Padova. He holds a Master Degree in Physics in Padova 2006, PhD in Physics in Trento 2010 on Quantum Monte Carl. Several postdocs, among which two Years at the Fritz-Haber Institute in Berlin under the supervision of Alexandre Tkatchenko.
We invite you to follow the seminar online in case you cannot make it in person.
- Meeting number: 2734 857 0382
- Meeting password: 4EWshCrDj87