Critical Entanglement for the Half-Filled One-Dimensional Extended Hubbard Model

A fundamental problem in many-body physics is the characterization and classification of the ground states for materials involving strongly correlated electrons. For the Extended Hubbard Model at half-filling in one dimension, this has historically required challenging Quantum Monte Carlo or DMRG calculations for large system sizes in order to extract phase diagram information. Within the last two decades, advances in quantum information theory, and in particular, conformal field theory results for entanglement entropy scaling, have enabled unprecedented accuracy in computing critical properties of ground states. In this talk, we present new techniques based on conformal field theory that enable rapid, cheap extraction of critical points and critical exponents at both 2^nd order and BKT transitions for open-boundary DMRG wave functions. The results of our study of the Extended Hubbard Model point to the broad applicability of the approach.