Plasma Oscillations in Holographic Quantum Matter
The interest in strongly correlated matter is motivated by the presence of a “strange metal” phase both in high temperature superconductors and in near charge neutral graphene, both being materials of immense scientific interest. The strange metal phase is a phase characterized by the absence of quasi-particles. This implies that conventional methods, such as perturbation theory in quantum field theory and Monte Carlo methods fall short of being able to describe the dynamics. Perhaps surprisingly, string theory provides a novel method, capable of precisely describing such systems - the holographic duality.
With the holographic duality, strongly coupled matter is mapped onto a weakly coupled gravity theory in one additional dimension, allowing for a conventional treatment of the dual system.
In this thesis, we extend the existing framework to also describe polarizing media. This is explicitly done in the form of new boundary conditions on the holographic dual, which deviate from previous holographic studies, and we contrast the quasinormal modes previously studied with the emergent collective modes we find for some studied models. We find new results, as well as confirm the predictions of less general models in their respective regions of validity and pave the way for more complex future models.
strongly correlated media
Subatomär, högenergi- och plasmafysik DP
A good candidate for a theoretical framework for these materials comes from string theory in the shape of holography. This allows one to circumvent solving a very hard problem, by instead solving an easier problem with an additional spatial dimension.
This thesis contributes to the larger picture of understanding these materials of the future, specifically by studying the theoretical electromagnetic response of such matter in a dynamical way, in various physically interesting settings. One particular direct application of this specialization is plasmonics, i.e. utilizing how the electrons can propagate information, a field of physics where graphene is already a material of particular interest.
Den kondenserade materiens fysik
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4992
PJ-salen, Fysikgården 2
Opponent: Koenraad Schalm, Universiteit Leiden, The Netherlands