Doping-dependent magnetization plateaus of a coupled spin-electron chain: exact results

TL;DR

This paper provides an exact solution for a coupled spin-electron chain, revealing doping-dependent magnetization plateaus and enhanced magnetocaloric effects influenced by mobile electron density.

Contribution

It introduces an exact analytical approach to study magnetization and magnetocaloric effects in a coupled spin-electron chain with variable doping.

Findings

Identification of seven distinct ground states.

Doping-dependent magnetization plateaus.

Enhanced magnetocaloric effect linked to electron density.

Abstract

A coupled spin-electron chain composed of localized Ising spins and mobile electrons is exactly solved in an external magnetic field within the transfer-matrix method. The ground-state phase diagram involves in total seven different ground states, which differ in the number of mobile electrons per unit cell and the respective spin arrangements. A rigorous analysis of the low-temperature magnetization process reveals doping-dependent magnetization plateaus, which may be tuned through the density of mobile electrons. It is demonstrated that the fractional value of the electron density is responsible for an enhanced magnetocaloric effect due to an annealed bond disorder of the mobile electrons.