Zeromode entanglement across a conformal defect
Abstract
We consider a freefermion chain with a conformal defect that features an extended zero mode, and study the entanglement properties in its mixed ground state. The zeromode induced degeneracy modifies the density of states in the singleparticle entanglement spectrum, which can be calculated via the full counting statistics. For a homogeneous chain, the resulting change in the Rényi entropy is derived analytically for arbitrary subsystem ratios in the thermodynamic limit. For a conformal defect located in the center, analogous results can be obtained for the halfchain entanglement. In particular, we observe parity effects for halfchains with even/odd sites, which do not decay with size.
 Publication:

Journal of Statistical Mechanics: Theory and Experiment
 Pub Date:
 May 2023
 DOI:
 10.1088/17425468/acd68f
 arXiv:
 arXiv:2303.10425
 Bibcode:
 2023JSMTE2023e3109C
 Keywords:

 entanglement;
 quantum defects;
 quantum criticality;
 CFT;
 Condensed Matter  Statistical Mechanics;
 Quantum Physics
 EPrint:
 doi:10.1088/17425468/acd68f