| dc.creator | Pereira, A. R. | |
| dc.creator | Pires, A. S. T. | |
| dc.creator | Moura, A. R. | |
| dc.date | 2019-01-25T12:17:59Z | |
| dc.date | 2019-01-25T12:17:59Z | |
| dc.date | 2014-05 | |
| dc.date.accessioned | 2023-09-27T21:14:41Z | |
| dc.date.available | 2023-09-27T21:14:41Z | |
| dc.identifier | 0304-8853 | |
| dc.identifier | https://doi.org/10.1016/j.jmmm.2014.01.006 | |
| dc.identifier | http://www.locus.ufv.br/handle/123456789/23187 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8957236 | |
| dc.description | In this paper we study the influence of the single-ion anisotropy in the two-dimensional biquadratic Heisenberg model (ABHM) on the square lattice at zero and finite low temperatures. It is common to represent the bilinear and biquadratic terms by J 1 1⁄4 J cos θ and J 2 1⁄4 J sin θ , respectively, and the many phases present in the model as a function of θ are well documented. However we have adopted a constant value for the bilinear constant (J 1 1⁄4 1) and small values of the biquadratic term (jJ 2 j o J 1 ). Specially, we have analyzed the quantum phase transition due to the single-ion anisotropic constant D. For values below a critical anisotropic constant D c the energy spectrum is gapless and at low finite temperatures the order parameter correlation has an algebraic decay (quasi-long-range order). Moreover,
in D o D c phase there is a transition temperature where the quasi-long-range order (algebraic decay) is lost and the decay becomes exponential, similar to the Berezinski–Kosterlitz–Thouless (BKT) transition. For D 4 D c , the excited states are gapped and there is no spin long-range order (LRO) even at zero temperature. Using Schwinger bosonic representation and Self-Consistent Harmonic Approximation (SCHA), we have studied the quantum and thermal phase transitions as a function of the bilinear and biquadratic constants. | |
| dc.format | pdf | |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Journal of Magnetism and Magnetic Materials | |
| dc.relation | Volume 357, Pages 45- 52, May 2014 | |
| dc.rights | 2014 Elsevier B.V. All rights reserved. | |
| dc.subject | Anisotropic Biquadratic Heisenberg Model | |
| dc.subject | Phase transition | |
| dc.subject | Schwinger boson | |
| dc.subject | SCHA | |
| dc.title | Phase transitions in the two-dimensional anisotropic biquadratic Heisenberg model | |
| dc.type | Artigo | |
