Speaker
Description
The sine-Gordon model is a paradigmatic quantum field theory that provides the low-energy effective description of many gapped 1D systems. Despite this fact, its complete thermodynamic description in all its regimes was lacking. In the talk, I will report the filling of this gap by deriving the Thermodynamic Bethe Ansatz framework that captures the thermodynamics of the model and serves as the basis of its hydrodynamic description. The latter opens the way to the large-scale description of the model’s non-equilibrium dynamics starting from an inhomogeneous initial state, where energy-charge separation can be observed. It also enables the calculation of transport coefficients such as the Drude weight and Onsager matrices. The Drude weight characterising the ballistic transport of the topological charge is found to exhibit a fractal-like dependence on the coupling, and the diffusive corrections also have interesting features. I will also discuss large-scale fluctuations of conserved charges and their currents and show that the distribution of the topological current is another quantity that shows fractal-like behaviour.
