Cluster fermionic Ising spin glass model with a transverse field

F.M. Zimmer, C.F. Silva and S.G. Magalhaes

Physica A: Statistical Mechanics and its Applications, 2010, vol. 389, issue 24, 5594-5601

Abstract: The fermionic Ising spin glass (SG) model in the presence of a transverse magnetic field Γ is studied within a cluster mean field theory. The model considers an infinite-range interaction among magnetic moments of clusters with a short-range ferromagnetic intracluster coupling J0. The spin operators are written as a bilinear combination of fermionic operators. In this quantum SG model, the intercluster disorder is treated by using a framework of one-step replica symmetry breaking (RSB) within the static approximation. The effective intracluster interaction is then computed by means of an exact diagonalization method. Results for several values of cluster size ns, Γ and J0 are presented. For instance, the specific heat can show a broad maximum at a temperature T∗ above the freezing temperature Tf, which is characterized by the intercluster RSB. The difference between T∗ and Tf is enhanced by Γ, which suggests that the quantum effects can increase the ratio T∗/Tf. Phase diagrams (T versus Γ) show that the critical temperature Tf(Γ) decreases for any values of ns and J0 when Γ increases until it reaches a quantum critical point at some value of Γc.

Keywords: Quantum spin glass; Transverse field (search for similar items in EconPapers)
Date: 2010
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378437110007855
Full text for ScienceDirect subscribers only. Journal offers the option of making the article available online on Science direct for a fee of $3,000

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:phsmap:v:389:y:2010:i:24:p:5594-5601

DOI: 10.1016/j.physa.2010.09.005

Access Statistics for this article

Physica A: Statistical Mechanics and its Applications is currently edited by K. A. Dawson, J. O. Indekeu, H.E. Stanley and C. Tsallis

More articles in Physica A: Statistical Mechanics and its Applications from Elsevier
Bibliographic data for series maintained by Catherine Liu ().