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Title: | Funções de correlação para uma cadeia de Ising decorada com spins Heisenberg numa estrutura diamante |
Other Titles: | Correlation functions for an Ising chain decorated with Heisenberg spins in a diamond structure |
Authors: | Rojas, Onofre Souza, Sérgio Martins de Leyva, Moisés Porfírio Rojas Sá Barreto, Francisco César de Pereira, Maria Socorro Seixas Souza, Sérgio Martins de Santos, Onofre Rojas Ferreira, Jordana Torrico |
Keywords: | Cadeias de spin Ising-Heisenberg Modelos quânticos de spin Cadeia de spin quântico Pseudo-transições Quase-fases Ising-Heisenberg chains Quantun spin models Quantic spin chain Pseudo-transitions Quasi-phases |
Issue Date: | 1-Oct-2018 |
Publisher: | Universidade Federal de Lavras |
Citation: | CARVALHO, I. M. Funções de correlação para uma cadeia de Ising decorada com spins Heisenberg numa estrutura diamante. 2018. 74 p. Dissertação (Mestrado em Física)–Universidade Federal de Lavras, Lavras, 2018. |
Abstract: | One-dimensional systems with short-range interactions cannot exhibit a long-range order at nonzero temperature. However, there are some particular one-dimensional models, such as the Ising-Heisenberg spin models with a variety of lattice geometries, which exhibit unexpected behavior similar to the temperature-driven phase transition. Although these pseudo-transitions are not true temperature-driven transitions showing only abrupt changes or sharp peaks in thermodynamic quantities, they may be confused while interpreting experimental data. Here we consider the spin-1/2Ising-XYZ diamond chain in the regime when the model exhibits temperature-driven pseudo-transitions. We provide a detailed investigation of various correlation functions between distant spins that illustrate the properties of quasi-phases separated by pseudo-transitions. Inevitably, all correlation functions present evidence of pseudo-transitions, which are supported by analytical solutions, which have been rigorously investigated around the pseudo-critical temperature. It is worth to mention that the correlation functions between distant spins have an extremely large correlation length at pseudo-critical temperature. |
URI: | http://repositorio.ufla.br/jspui/handle/1/30872 |
Appears in Collections: | Física - Mestrado (Dissertações) |
Files in This Item:
File | Description | Size | Format | |
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DISSERTAÇÃO_Funções de correlação para uma cadeia de ising decorada com spins Heisenberg numa estrutura diamante.pdf | 2,31 MB | Adobe PDF | View/Open |
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