Speaker: Máté Lencsés (RMI)

Title: The scaling region of the tricritical Ising model

Place: Building 3, Meeting room

Date: 27 January 2023,  14 p.m.


The two-dimensional Ising model with vacancies has a tricritical point described by a conformal field theory. Recently we investigated various combinations of relevant perturbations of the tricritical point. I will present our results for the form factors of the leading and subleading order and disorder operators in the integrable thermal perturbation. In the ordered phase, there are two degenerate ground states and different types of kinks interpolating between them. A small magnetic field lifts the degeneracy and confines the kinks to mesons. We found that kinks of different types can also form mesons and extended the semi-classical method to approximate their masses. Perturbing with the subleading magnetic field also leads to degenerate ground states, which can be unbalanced by the thermal operator, leading to the confinement of kinks not generated by a symmetry-breaking field. In both cases, one can simulate the "fate of the false vacuum" as a quantum quench protocol. Using the truncated conformal space approach, we showed that the bubble nucleation rate is consistent with results in the literature. Finally, I will discuss the multicritical generalization of the Yang-Lee edge singularity.