Second Rényi entropy and annulus partition function for onedimensional quantum critical systems with boundaries
Abstract
We consider the entanglement entropy in critical onedimensional quantum systems with open boundary conditions. We show that the second Rényi entropy of an interval away from the boundary can be computed exactly, provided the same conformal boundary condition is applied on both sides. The result involves the annulus partition function. We compare our exact result with numerical computations for the critical quantum Ising chain with open boundary conditions. We find excellent agreement, and we analyse in detail the finitesize corrections, which are known to be much larger than for a periodic system.
 Publication:

SciPost Physics
 Pub Date:
 April 2022
 DOI:
 10.21468/SciPostPhys.12.4.141
 arXiv:
 arXiv:2112.01929
 Bibcode:
 2022ScPP...12..141E
 Keywords:

 Mathematical Physics;
 Condensed Matter  Statistical Mechanics;
 High Energy Physics  Theory
 EPrint:
 17+5 pages, 10 figures