Ferromagnetic Peierls insulator state in $\mathit{A}$Mg$_4$Mn$_6$O$_{15}$ ($\mathit{A}$ = K, Rb, Cs)

T. Yamaguchi; K. Sugimoto; Y. Ohta; Y. Tanaka; H. Sato

doi:10.1103/PhysRevB.97.161103

paper

Ferromagnetic Peierls insulator state in $A$ Mg $_{4}$ Mn $_{6}$ O $_{15}$ ( $A$ = K, Rb, Cs)

arXiv:1802.06536 · doi:10.1103/PhysRevB.97.161103

Abstract

Using the density-functional-theory based electronic structure calculations, we study the electronic state of recently discovered mixed-valent manganese oxides $A$ Mg $_{4}$ Mn $_{6}$ O $_{15}$ ( $A =$ K, Rb, Cs), which are fully spin-polarized ferromagnetic insulators with a cubic crystal structure. We show that the system may be described as a three-dimensional arrangement of the one-dimensional chains of a $2 p$ orbital of O and a $3 d$ orbital of Mn running along the three axes of the cubic lattice. We thereby argue that in the ground state the chains are fully spin polarized due to the double-exchange mechanism and are distorted by the Peierls mechanism to make the system insulating.

5 pages, 5 figures

Ferromagnetic Peierls insulator state in AMg4​Mn6​O15​ (A = K, Rb, Cs)

Abstract

Ferromagnetic Peierls insulator state in $A$ Mg $_{4}$ Mn $_{6}$ O $_{15}$ ( $A$ = K, Rb, Cs)