Entropy driven dimerization in a one-dimensional spin-orbital model

2002/12/16 by Jesko Sirker, J. Sirker, Giniyat Khaliullin +1 · 4 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.67.100408

published as Phys. Rev. B 67, 100408 (2003) · 5 pages, 4 figures

arxiv created 2002/12/16 · openalex publication_date 2003/03/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We study a 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 YVO₃.

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