Finite-size scaling behavior in trapped systems
arXiv:1003.1075 · doi:10.1103/PhysRevE.81.051122
Abstract
Numerical transfer-matrix methods are applied to two-dimensional Ising spin systems, in presence of a confining magnetic field which varies with distance to a "trap center", proportionally to , . On a strip geometry, the competition between the "trap size" and the strip width, , is analysed in the context of a generalized finite-size scaling {\em ansatz}. In the low-field regime , we use conformal-invariance concepts in conjunction with a linear-response approach to derive the appropriate (-dependent) limit of the theory, which agrees very well with numerical results for magnetization profiles. For high fields , correlation-length scaling data broadly confirms an existing picture of -dependent characteristic exponents. Standard spin-1/2 and spin-1 Ising systems are considered, as well as the Blume-Capel model.
RevTeX, 8 pages, 7 .eps figures (published version