Dynamically generated dimension reduction and crossover in a spin orbital model

TL;DR

This paper investigates a spin-orbital model revealing how fluctuations induce first-order phase transitions and lead to dynamic dimension reduction and reentrant spin transitions near critical points.

Contribution

It introduces a novel analysis of fluctuation-driven phase transitions and dynamic dimension reduction in a spin-orbital system, with implications for understanding complex magnetic materials.

Findings

Fluctuations cause a first-order transition from paramagnetic to C-type order.

Close to the transition, the system exhibits dynamically generated dimension reduction.

Multiple spin reentrant transitions occur near the critical point.

Abstract

We study a spin orbital model in which the spin-spin interaction couples linearly to the orbital isospin. Fluctuations drive the transition from paramagnetic state to C type ordered state into a strongly first order one, as observed in $V_2O_3$. At T=0, there is a FOCS to FOGS transition. Close to the transition point, the system shows dynamically generated dimension reduction and crossover, resulting in one or more spin reentrant transitions.