Description
In this talk, I am going to talk about two topics. First, I will introduce how a single PT-symmetric non-Hermitian impurity can induce exceptional points (EP) on critical Hermitian SSH models. From this, we relate the existence of EP to several physical observables that serve as evidence that the underlying structure is governed by certain non-unitary CFT. In addition, some boundary effects will be noted. On the second topic, sharing the similar structure, I will introduce three interface CFT setups motivated by hep-th setup, and discuss our recent results on the related topic. In both topics, I will try to set up the field theory description, but both of which are still work in progress.