Thermally activated Peierls dimerization in ferromagnetic spin chains

TL;DR

This paper shows that thermal fluctuations can induce Peierls dimerization in ferromagnetic spin chains, with analysis using spin-wave theory and DMRG, relevant for transition metal oxides.

Contribution

It introduces the concept of thermally activated Peierls dimerization in ferromagnetic chains and analyzes its mechanisms and implications.

Findings

Peierls dimerization can be thermally activated in ferromagnetic chains.

Spin-wave theory and DMRG effectively analyze the phenomenon.

Relevance to transition metal oxides is discussed.

Abstract

We demonstrate that a Peierls dimerization can occur in ferromagnetic spin chains activated by thermal fluctuations. The dimer order parameter and entanglement measures are studied as functions of the modulation of the magnetic exchange interaction and temperature, using a spin-wave theory and the density-matrix renormalization group. We discuss the case where a periodic modulation is caused by spin-phonon coupling and the case where electronic states effectively induce such a modulation. The importance of the latter for a number of transition metal oxides is highlighted.