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Interplay between electron-electron and electron-phonon interactions in nanostructures

Interplay between electron-electron and electron-phonon interactions in nanostructures

PhD project title and outline, including interdisciplinary dimension:
Interplay between electron-electron and electron-phonon interactions in nanostructures

The interaction between electrons and atomic vibrations (phonons) is a beautiful example of how a process from the
heart of quantum mechanics can impact on us every day: this is how current heats up wires making your toaster work.
It is also a key process behind many “invisible” but far-reaching problems: the functionality of nanoscale electronic
devices, the de-excitation of photo-excited systems, and thermoelectric effects. Theoretically, electron-phonon
scattering is a tough problem, made doubly so by the fact that electrons interact also with each other. This has a direct
bearing on how electrons interact with thermal vibrations: this hinges on how electrons behave in the immediate
proximity of nuclei, which in turn depends very much on the influence of the other electrons hovering by. Despite big
strides in the theory and simulation of electron dynamics and atomic motion in nanoscale systems, this crucial problem
– the interplay between electron-phonon and electron-electron scattering – remains rather open. There are
procedures used in practical calculations, but their foundations and range of validity require fresh input from a new
direction. This project combines many-body theory (MBT) with a method for correlated electron-ion dynamics (CEID),
developed between QUB and collaborators in London, to analyse this problem in the context of nanodevices and
photo-excited systems, with the aim of reaching a deeper understanding and a working procedure for the
simultaneous description of electron-electron and electron-phonon dynamics in single-particle methods such as timedependent
Hartree-Fock and density-functional frameworks. This is challenging theoretical and computational work at
the intersection between physics, chemistry and engineering, pulling together techniques from different fields, but
with great pay-offs and benefits in terms of transferable skills.

Co-supervisors: Dr Tchavdar Todorov (Maths and Physics) and Dr Myrta Grüning (Maths and Physics) 

External Partner/Organisation:

Prof. Jan van Ruitenbeek (Leiden University)
Dr. Andrea Marini (Italian Research Council)
Prof. Kieron Burke (UC Irvine) and Prof. Neepa Maitra (Hunter, CUNY)

SCM  (Amsterdam)
Atomistic Simulation Centre, QUB