[en] We consider a general kinetic model for a chain of three-state Potts spins. From the time-evolution operator we infer points in two-dimensional Potts systems where certain spin correlations have one-dimensional character and the model is exactly solvable. This occurs in square lattice models with different kinds of competing interactions
Journal
[en] The authors study the anisotropic Ising model on a square lattice with free boundary conditions. A simple explicit result is obtained for the surface magnetization of a system which is inhomogeneous near the surface. The corner magnetization is investigated for a 90 degrees corner in a homogeneous anisotropic system. From the numerical results an analytical formula is found
Journal
[en] We consider a chain of free electrons with periodically switched dimerization and study the entanglement entropy of a segment with the remainder of the system. We show that it evolves in a stepwise manner towards a value proportional to the length of the segment and displays in general slow oscillations. For particular quench periods and full dimerization an explicit solution is given. Relations to equilibrium lattice models are pointed out. (Abstract Copyright [2008], Wiley Periodicals, Inc.)
Journal
Annalen der Physik (Leipzig); ISSN 0003-3804; 
; v. 17(6); p. 410-423
; v. 17(6); p. 410-423
[en] We study zero-temperature XX chains and transverse Ising chains and join an initially separate finite piece on one or on both sides to an infinite remainder. In both critical and non-critical systems we find a typical increase of the entanglement entropy after the quench, followed by a slow decay towards the value of the homogeneous chain. In the critical case, the predictions of conformal field theory are verified for the first phase of the evolution, while at late times a step structure can be observed
Journal
Journal of Statistical Mechanics; ISSN 1742-5468; ; v. 2008(01); [15 p.]
; v. 2008(01); [15 p.]