When a quantum field theory possesses topological excitations in a phase with spontaneously broken symmetry, these are created by operators which are non-local with respect to the order parameter. Due to non-locality, such disorder operators have non-trivial correlation functions even in free massive theories. In two dimensions, these correlators can be expressed exactly in terms of solutions of non-linear differential equations. The correlation functions of the one-parameter family of non-local operators in the free charged bosonic and fermionic models are the inverse of each other. We point out a simple derivation of this correspondence within the form factor approach
In [1] a new bosonization procedure has been illustrated, which allows us to express a fermionic Gaussian system in terms of commuting variables by introducing an extra dimension. The Fermi–Bose duality principle established in this way also has many potential applications outside the context of gauge field theories in which it has been developed. In this work we present an application to the problem of averaging the correlation functions with respect to random potentials in disordered systems and similar problems.
In this paper, we revisit the operator-state correspondence in the Majorana conformal field theory (CFT) with emphasis on its semion representation. Whereas the semion representation (or Z2 extension of the chiral Ising CFT) gives a concise ``Abelian'' (or invertible) representation at the level of fusion rules and quantum states, there exists a subtlety when considering the chiral multipoint correlation function. In this sense, the operator-state correspondence in the semion sector of the fermionic theory inevitably contains a difficulty coming from its anomalous conformal dimension 1/16 as a Z2 symmetry operator. By analyzing the asymptotic behaviors of the existing correlation functions, we propose a nontrivial correspondence between the chiral conformal blocks and bulk correlation functions containing both order and disorder fields. One can generalize this understanding to ZN models or fractional supersymmetric models (for which there exist long-standing open problems). We expect that this may improve our understanding of the simple current extension of CFT, which commonly appears in the studies of topologically ordered systems.