The Blume-Emery-Griffiths Spin Glass and Inverted Tricritical Points

TL;DR

This paper investigates the phase behavior of the Blume-Emery-Griffiths spin glass model in three dimensions, revealing complex phase transitions including inverted tricritical points and reentrant phenomena using renormalization-group theory.

Contribution

It provides the first detailed analysis of phase topology and transition types in the Blume-Emery-Griffiths spin glass model in three dimensions.

Findings

Identification of inverted tricritical points.

Discovery of reentrant spin-glass phases.

Complex phase diagram topology with disconnected regions.

Abstract

The Blume-Emery-Griffiths spin glass is studied by renormalization-group theory in d=3. The boundary between the ferromagnetic and paramagnetic phases has first-order and two types of second-order segments. This topology includes an inverted tricritical point, first-order transitions replacing second-order transitions as temperature is lowered. The phase diagrams show disconnected spin-glass regions, spin-glass and paramagnetic reentrances, and complete reentrance, where the spin-glass phase replaces the ferromagnet as temperature is lowered for all chemical potentials.