Events
Dr. Debanjan Chowdhury, MIT
“Strange Quantum Matter: Fermi Surfaces Sans Fermi Liquids”
Abstract: One of the most successful approaches for describing the collective properties of a large number of interacting electrons in a solid-state system relies on a profound concept introduced originally by Landau in the 1950s. The notion of electronic 'quasiparticles', in terms of which the complex many-electron problem becomes much simpler, is one of the cornerstones of the theory of quantum materials. However, a growing number of strongly correlated quantum materials display phenomenology that has forced us to confront the existence of quantum matter for which the concept of electronic quasiparticles does not apply. I will present examples of qualitatively new experimental phenomena that emerge in parent states of high-temperature superconductors and candidate topological materials, purely as a result of strong interactions. Finally, I will also present new experimental results on twisted bilayer graphene, where much of the phenomenology described in the rest of my talk can be engineered in a highly controlled fashion by tuning the electronic bandwidth and carrier density.
