Finite-size scaling behavior in trapped systems

Autor: de Queiroz, S. L. A., Santos, R. R. dos, Stinchcombe, R. B.
Rok vydání: 2010
Předmět:
Zdroj: Physical Review E 81, 051122 (2010)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevE.81.051122
Popis: Numerical transfer-matrix methods are applied to two-dimensional Ising spin systems, in presence of a confining magnetic field which varies with distance $|{\vec x}|$ to a "trap center", proportionally to $(|{\vec x}|/\ell)^p$, $p>0$. On a strip geometry, the competition between the "trap size" $\ell$ and the strip width, $L$, is analysed in the context of a generalized finite-size scaling {\em ansatz}. In the low-field regime $\ell \gg L$, we use conformal-invariance concepts in conjunction with a linear-response approach to derive the appropriate ($p$-dependent) limit of the theory, which agrees very well with numerical results for magnetization profiles. For high fields $\ell \lesssim L$, correlation-length scaling data broadly confirms an existing picture of $p$-dependent characteristic exponents. Standard spin-1/2 and spin-1 Ising systems are considered, as well as the Blume-Capel model.
Comment: RevTeX, 8 pages, 7 .eps figures (published version
Databáze: arXiv