A method that reveals the multi-level ultrametric tree hidden in p-spin glass like systems

TL;DR

This paper introduces a straightforward method to uncover the multi-level ultrametric structure in p-spin glass systems, extending the RSB approach to include saddle points for a more detailed energy landscape analysis.

Contribution

It presents a simple, transparent extension of the RSB method that reveals the multi-level ultrametric organization in p-spin glasses including saddle points.

Findings

Ultrametric organization with many levels identified in p-spin models.

The Parisi function q(x) encodes the ultrametric structure.

Method applicable to models with saddle points.

Abstract

In the study of disordered models like spin glasses the key object of interest is the rugged energy hypersurface defined in configuration space. The statistical mechanics calculation of the Gibbs-Boltzmann Partition Function gives the information necessary to understand the equilibrium behavior of the system as a function of the temperature but is not enough if we are interested in more general aspects of the hypersurface: it does not give us, for instance, the different degrees of ruggedness at different scales. In the context of the Replica Symmetry Breaking (RSB) approach we discuss here a rather simple extension that can provide a much more detailed picture. The attractiveness of the method relies in that it is conceptually transparent and the additional calculations are rather straightforward. We think that this approach reveals an ultrametric organisation with many levels in models like p-spin glasses when we include saddle points. In this first paper we present the detailed calculations for the spherical p-spin glass model where we discover that the corresponding decreasing Parisi function $q(x)$ codes this hidden ultrametric organisation.