Comment on “Quantum coherence in an exactly solvable one-dimensional model with defects”

¹ B. I. Verkin Institute for Low Temperature Physics and Engineering of the National Ukrainian Academy of Sciences - 47, Lenin ave., Kharkov, 310164, Ukraine
² Institute of Theoretical Physics, Chalmers University of Technology and Göteborg University - S-412 96, Göteborg, Sweden

Received: 1 December 1995
Accepted: 23 May 1996

Abstract

In a recent paper by Schmitteckert et al., an exactly solvable XXZ chain with defects was studied. We here point out that, for this type of model, the critical exponents for the asymptotic correlation functions are insensitive to the presence of defects. Also, the defects do not enhance the persistent current of the equivalent fermionic model, contrary to a claim by Schmitteckert et al.