Mutual Information and Boson Radius in c=1 Critical Systems in One Dimension

Understand

We study the generic scaling properties of the mutual information between two disjoint intervals, in a class of one-dimensional quantum critical systems described by the c=1 bosonic field theory.

• A numerical analysis of a spin-chain model reveals that the mutual information is scale-invariant and depends directly on the boson radius.
• We interpret the results in terms of correlation functions of branch-point twist fields.
• The present study provides a new way to determine the boson radius, and furthermore demonstrates the power of the mutual information to extract more refined information of conformal field theory than the central charge.