Letian Ding | Searcharxiv

arXiv2008

Subarea law of entanglement in nodal fermionic systems

We investigate the subarea law scaling properties of the block entropy in bipartite fermionic systems which do not have a finite Fermi surface. It is found that in gapped regimes the leading subarea term is a negative constant, whereas in critical regimes with point nodes the leading subarea law is a logarithmic additive term. At the phase boundary that separates the critical and non-critical regimes, the subarea scaling shows power-law behavior.

cond-mat.str-el↗

arXiv2006

Scaling Behavior of Entanglement in Two- and Three-Dimensional Free Fermions

Exactly solving a spinless fermionic system in two and three dimensions, we investigate the scaling behavior of the block entropy in critical and non-critical phases. The scaling of the block entropy crucially depends on the nature of the excitation spectrum of the system and on the topology of the Fermi surface. Noticeably, in the critical phases the scaling violates the area law and acquires a logarithmic correction \emph{only} when a well defined Fermi surface exists in the system. When the area law is violated, we accurately verify a conjecture for the prefactor of the logarithmic correction, proposed by D. Gioev and I. Klich [quant-ph/0504151].

quant-ph↗