"Clustering of fractionalised excitations in frustrated magnets" Ludovic Jaubert (LOMA, University of Bordeaux)

Date & Time: Sep 5th, 14:00-15:00

Venue: C016, Lab1

Spearker: Ludovic Jaubert, CNRS researcher at the LOMA, University of Bordeaux

Title: Clustering of fractionalised excitations in frustrated magnets

Abstract:

Fractionalisation is an ubiquitous phenomenon in topological states of matter, found in the fractional quantum Hall effect, but also as topological excitations emerging from spin liquids.  Here we will explore how the interaction between these excitations can be responsible for a rich diversity of phases at equilibrium, as well as out-of-equilibrium dynamics, dominated by topological bottlenecks and multi-scale energy barriers. We will specifically discuss the Ising model on pyrochlore and kagome lattices with 1st, 2nd and 3rd nearest neighbour. For a specific ratio between the latter two couplings, this model can be recast as a Hamiltonian of interacting topological charges under the constraint of Gauss’ law. But while this Gauss law is imposed, the coupling between fractionalised charges can be tuned from natural to "unnatural", i.e. where same-sign charges attract each other. This unconventional coupling induces the clustering of fractionalised excitations over extended regions. We will present the consequences of this clustering on the nature of novel spin liquids, multi-scale relaxation processes, and their potential signature in neutron scattering experiments.