Thermodynamics of the frustrated one-dimensional spin-1/2 Heisenberg ferromagnet in a magnetic field

TL;DR

This paper investigates the low-temperature thermodynamics of a frustrated 1D spin-1/2 Heisenberg ferromagnet in a magnetic field, revealing power-law behaviors and multiple maxima in specific heat.

Contribution

It introduces a combined Green-function and exact diagonalization approach to analyze thermodynamic properties of the frustrated ferromagnetic chain under magnetic fields.

Findings

Power-law relations for susceptibility maxima

Two maxima observed in specific heat at low fields

Thermodynamic quantities characterized across temperature range

Abstract

We calculate the low-temperature thermodynamic quantities (magnetization, correlation functions, transverse and longitudinal correlation lengths, spin susceptibility, and specific heat) of the frustrated one-dimensional spin-half J1-J2 Heisenberg ferromagnet, i.e. for J2< 0.25|J1|, in an external magnetic field using a second-order Green-function formalism and full diagonalization of finite systems. We determine power-law relations for the field dependence of the position and the height of the maximum of the uniform susceptibility. Considering the specific heat at low magnetic fields, two maxima in its temperature dependence are found.