Abstract
In this paper we study two non-mean-field (NMF) spin models built on a hierarchical lattice: the hierarchical Edward–Anderson model (HEA) of a spin glass, and Dyson’s hierarchical model (DHM) of a ferromagnet. For the HEA, we prove the existence of the thermodynamic limit of the free energy and the replica-symmetry-breaking (RSB) free-energy bounds previously derived for the Sherrington–Kirkpatrick model of a spin glass. These RSB mean-field bounds are exact only if the order-parameter fluctuations (OPF) vanish: given that such fluctuations are not negligible in NMF models, we develop a novel strategy to tackle part of OPF in hierarchical models. The method is based on absorbing part of OPF of a block of spins into an effective Hamiltonian of the underlying spin blocks. We illustrate this method for DHM and show that, compared to the mean-field bound for the free energy, it provides a tighter NMF bound, with a critical temperature closer to the exact one. To extend this method to the HEA model, a suitable generalization of Griffith’s correlation inequalities for Ising ferromagnets is needed: since correlation inequalities for spin glasses are still an open topic, we leave the extension of this method to hierarchical spin glasses as a future perspective.
Similar content being viewed by others
References
Panchenko, D.: The Parisi ultrametricity conjecture. Ann. Math. 177(1), 383–393 (2013)
Parisi, G.: Order parameter for spin-glasses. Phys. Rev. Lett. 50(24), 1946–1948 (1983)
Guerra, F.: Broken replica symmetry bounds in the mean field spin glass model. Commun. Math. Phys. 233(1), 1–12 (2003)
Talagrand, M.: The Parisi formula. Ann. Math. 163(1), 221–264 (2006)
Young, A.P.: Numerical simulations of spin glasses: methods and some recent results In: Computer Simulations in Condensed Matter Systems: from Materials to Chemical Biology vol. 2, pp. 31–44. Springer, Berlin (2006)
Franz, S., Jörg, T., Parisi, G.: Overlap interfaces in hierarchical spin-glass models. J. Stat. Mech. 2(2), P02002 (2009)
Castellana, M.: Real-space renormalization group analysis of a non-mean-field spin-glass. Europhys. Lett. 95(4), 47014 (2011)
Angelini, M.C., Parisi, G., Ricci-Tersenghi, F.: Ensemble renormalization group for disordered systems. Phys. Rev. B 87(13), 134201 (2013)
Dyson, F.J.: Existence of a phase transition in a one-dimensional Ising ferromagnet. Commun. Math. Phys. 12(2), 91–107 (1969)
Bleher, P.M., Sinai, J.G.: Investigation of the critical point in models of the type of Dyson’s hierarchical models. Commun. Math. Phys. 33(1), 23–42 (1973)
Griffiths, R.B.: Correlations in Ising ferromagnets III. Commun. Math. Phys. 6(2), 121–127 (1967)
Griffiths, R.B.: Correlations in Ising ferromagnets. II. External magnetic fields. J. Math. Phys. 8, 484 (1967)
Morita, S., Nishimori, H., Contucci, P.: Griffiths inequalities for the gaussian spin glass. J. Phys. A 37(18), L203 (2004)
Contucci, P., Lebowitz, J.: Correlation inequalities for spin glasses. Ann. Inst. Henri Poincaré 8(8), 1461–1467 (2007)
Guerra, F., Toninelli, F.L.: The thermodynamic limit in mean field spin glass models. Commun. Math. Phys. 230(1), 71–79 (2002)
Bolthausen, E., Bovier, A.: Spin Glasses. Springer, Berlin (2007)
Gallavotti, G., Miracle-Sole, S.: Statistical mechanics of lattice systems. Commun. Math. Phys. 5(5), 317–323 (1967)
Acknowledgments
M. Castellana is grateful to S. Franz for useful discussions, to NSF for funding through Grants PHY-0957573 and CCF-0939370, to the Human Frontiers Science Program, to the Swartz Foundation, and to the W. M. Keck Foundation for financial support. A. Barra is grateful to MIUR for funding trough the grant FIRB RBFR08EKEV, and to Sapienza Università di Roma and to GNFM-INdAM for partial financial support. F. Guerra is grateful to Sapienza Università di Roma and to INFN for partial financial support.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Castellana, M., Barra, A. & Guerra, F. Free-Energy Bounds for Hierarchical Spin Models. J Stat Phys 155, 211–222 (2014). https://doi.org/10.1007/s10955-014-0951-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10955-014-0951-9