Marcus Tornsö, fysik

​Titel på doktorsavhandling: Plasma Oscillations in Holographic Quantum Matter


In this thesis we explore strongly correlated matter in the framework of holographic duality. Specifically, we examine the quasinormal modes of such systems, and we extend the current framework to efficiently and naturally cover plasmons and other collective modes that may be found within strongly correlated 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.
Huvudhandledare: Ulf Gran
Examinator: Martin Cederwall
Opponent: Koenraad Schalm​
Kategori Disputation
Plats: Online via Zoom
Tid: 2021-09-24 09:00
Sluttid: 2021-09-24 12:00

Sidansvarig Publicerad: to 16 sep 2021.