Inverse freezing in the Hopfield Fermionic Ising Spin Glass

التفاصيل البيبلوغرافية
العنوان: Inverse freezing in the Hopfield Fermionic Ising Spin Glass
المؤلفون: Magalhaes, S. G., Morais, C. V., Zimmer, F. M.
سنة النشر: 2009
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Superconductivity
الوصف: In this work it is studied the Hopfield fermionic spin glass model which allows interpolating from trivial randomness to a highly frustrated regime. Therefore, it is possible to investigate whether or not frustration is an essential ingredient which would allow this magnetic disordered model to present naturally inverse freezing by comparing the two limits, trivial randomness and highly frustrated regime and how different levels of frustration could affect such unconventional phase transition. The problem is expressed in the path integral formalism where the spin operators are represented by bilinear combinations of Grassmann variables. The Grand Canonical Potential is obtained within the static approximation and one-step replica symmetry breaking scheme. As a result, phase diagrams temperature {\it versus} the chemical potential are obtained for several levels of frustration. Particularly, when the level of frustration is diminished, the reentrance related to the inverse freezing is gradually suppressed.
Comment: 10 pages, 4 figures, accepted for publication in Phys. Rev. B
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.81.014207
URL الوصول: http://arxiv.org/abs/0912.4469
رقم الأكسشن: edsarx.0912.4469
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.81.014207