Entropy Driven Dimerization in a One-Dimensional Spin-Orbital Model

Abstract

We study a new version of the one-dimensional spin-orbital model with spins S=1 relevant to cubic vanadates. At small Hund's coupling J_H we discover dimerization in a pure electronic system solely due to a dynamical spin-orbital coupling. Above a critical value J_H, a uniform ferromagnetic state is stabilized at zero temperature. More surprisingly, we observe a temperature driven dimerization of the ferrochain, which occurs due to a large entropy released by dimer states. This dynamical dimerization seems to be the mechanism driving the peculiar intermediate phase of YVO_3.

5 pages, 4 figures

References in corpus (1)

• Temperature driven crossover phenomena in the correlation lengths of the one-dimensional t-J model

Cited by in corpus (2)

• Real-time dynamics at finite temperature by DMRG: A path-integral approach
• Thermodynamics of a one-dimensional S=1/2 spin-orbital model