2013/04/30 by Helen Au-Yang, Michael E. Fisher · 1 citation
Physics and Astronomy · #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.88.032147
published as Phys. Rev. E 88, 032147 (2013) · 14 pages, double-column format, 12 figures. Version 3 has further improvements over versions 1 and 2
arxiv created 2013/09/11 · arxiv updated 2013/10/30
The specific heats of exactly solvable alternating layered planar Ising models with strips of width m1 lattice spacings and ``strong'' couplings J1 sandwiched between strips of width m2 and ``weak'' coupling J2, have been studied numerically to investigate the effects of connectivity and proximity. We find that the enhancements of the specific heats of the strong layers and of the overall or `bulk' critical temperature, Tc(J1,J2;m1,m2), arising from the collective effects reflect the observations of Gasparini and coworkers in experiments on confined superfluid helium. Explicitly, we demonstrate that finite-size scaling holds in the vicinity of the upper limiting critical point T1c (∝ J1/kB) and close to the corresponding lower critical limit T2c (∝ J2/kB) when m1 and m2 increase. However, the residual \it enhancement, defined via appropriate subtractions of leading contributions from the total specific heat, is dominated (away from T1c and T2c) by a decay factor 1/(m1+m2) arising from the \it seams (or boundaries) separating the strips; close to T1c and T2c the decay is slower by a factor ln m1 and ln m2, respectively.