Entanglement Renormalization for Interacting Field Theories

Understand

A general method to build the entanglement renormalization (cMERA) for interacting quantum field theories is presented.

• We improve upon the well-known Gaussian formalism used in free theories through a class of variational non-Gaussian wavefunctionals for which expectation values of local operators can be efficiently calculated analytically and in a closed form.
• The method consists of a series of scale-dependent nonlinear canonical transformations on the fields of the theory under consideration.
• Here, the $\lambda\, \phi^4$ and the sine-Gordon scalar theories are used to illustrate how non-perturbative effects far beyond the Gaussian approximation are obtained by considering the energy functional and the correlation functions of the theory.