Bipartite fidelity of critical lattice models (remote talk)
par
Gilles Parez (UCLouvain)
→
Europe/Paris
Description
The bipartite fidelity (BF) is an entanglement measure introduced in 2011 by J. Dubail and J.-M. Stéphan. For a quantum system, it is defined as the overlap between the groundstate of the whole system and the tensor product of the groundstates of two complementary subsystems. For 1d quantum critical systems, the scaling limit of the BF is universal and can be obtained with 1+1d conformal field theory (CFT) calculations on domains that depend on the boundary conditions of the systems. In this talk, I will discuss recent progress we made in two main directions: (i) in the CFT picture, one field inserted on the domain is logarithmic, and (ii) the whole system has periodic boundary conditions, whereas the subsystems both have either open or periodic ones. For both directions we generalise or derive new CFT predictions that we compare with analytical or numerical lattice calculations and find perfect agreement. In particular, I will describe some analytical lattice results that we obtained using the Temperley-Lieb algebra. I will also discuss some potential further development, such as interesting connections between the BF and the symmetry resolved entanglement entropies. This talk is based on the papers arXiv:1902.02246 andarXiv:2008.08952.