Speaker
Description
Liquid phases are exotic phases of matter that arise in many-body interacting systems. In contrast to more conventional phases, such liquids remain disordered down to zero temperature. Nevertheless, despite the apparent lack of order, their local degrees of freedom are highly correlated.
However, liquid phases can be fragile. The unavoidable coupling to the degrees of freedom of their environment may render them unstable and radically alter their properties. Thus, to guide the experimental search for liquid phases, it is critical to determine their stability to environment-induced dissipation.
The importance of considering the coupling to the environment was demonstrated by recent quantum Monte Carlo simulations which established that the ground-state of the spin-1/2 Heisenberg chain, a well-known spin liquid, is unstable in the presence of an infinitesimal coupling to an ohmic bath. This work opened the prospect of similar phenomena for other liquid phases.
Motivated by these results, this thesis will extend the stability analysis to other liquid phases. Namely, we will examine the charge liquid phase realized in the one-dimensional Bose-Hubbard model, and quantum spin ice - a paradigmatic three-dimensional quantum spin liquid. To perform this analysis, we will develop an algorithm specifically designed to deal with the action of the environment. Concretely, our approach uses a quantum Monte Carlo method based on a continuous-time path integral algorithm with worm update.
