Detta är en digital seminarieserie i kondenserade materiens fysik och atomfysik, med syfte att koppla samman forskare från olika nordiska universitet. Samtalen är informella och ska inspirera till diskussioner och interaktioner.
While a significant fraction of topological materials has been characterized using symmetry requirements, the last couple of years have witnessed the rise of new topologies that arise in multi-level system and go beyond all previously-known classification. Topological transitions occur via band touching points and as such Dirac or Weyl nodes have been familiar and attracting a lot of attention in various contexts. Here, I will show that in systems with C2T or PT symmetry, band singularities can be characterised by a non-Abelian frame charges. I will demonstrate momentum space braiding of these topological singularities and discuss their observable signatures including the peculiarities of the associated edge states. In particular, I will show that the combination of periodic driving and these recent multi-gap topological insights galvanize a new direction, arriving at new anomalous topological phases in out-of-equilibrium settings that have no static counterparts. I will identify observable signatures within reach of state-of-the-art quantum simulators ranging from optical lattices to kicked quantum rotors, and present specific interferometry schemes.
Zoom-länk: https://nordita.org/zoom/nvcms