Journal: | Brazilian journal of physics |
Database: | PERIÓDICA |
System number: | 000408623 |
ISSN: | 0103-9733 |
Authors: | Nogueira, Yamilles1 Viana, J. Roberto1 Sousa, J. Ricardo de2 |
Institutions: | 1Universidade Federal do Amazonas, Departamento de Fisica, Manaus, Amazonas. Brasil 2Universidade Federal de Minas Gerais, Instituto de Ciencias Exatas, Belo Horizonte, Minas Gerais. Brasil |
Year: | 2007 |
Season: | Jun |
Volumen: | 37 |
Number: | 2A |
Pages: | 331-334 |
Country: | Brasil |
Language: | Inglés |
Document type: | Artículo |
Approach: | Experimental, analítico |
English abstract | The van Hemmen model with a random field is studied to analyze the tricritical behavior in the Ising spin glass phase. The free energy and phase diagram (T versus H and T versus Jo/J, where H is the root mean square deviation of the magnetic field, Jo and J are the ferromagnetic and root mean square deviation exchange, respectively) are calculated for the model with discrete (or bimodal) and Gaussian distributions. For the case of the bimodal probability distribution (random field and exchange), we have the presence of three ordered phases, namely: spin glass (SG), mixed (P) and ferromagnetic (F). The root mean square deviation of the random field H destroys the spin glass and mixed phases. The mixed phase doesn't appear with Gaussian distribution. In the plane T versus H, we analyze the tricritical behavior for the case of the bimodal distribution, and we compare it with the results obtained by using the Gaussian distribution that presents only second-order phase transition |
Disciplines: | Física y astronomía |
Keyword: | Física, Física de partículas y campos cuánticos, Vidrios de espín |
Keyword: | Physics and astronomy, Particle physics and quantum fields, Physics, Spin glasses |
Full text: | Texto completo (Ver PDF) |