Details

Autor(en) / Beteiligte

• McNally, D. E.
• Simonson, J. W.
• Post, K. W.
• Yin, Z. P.
• Pezzoli, M.
• Smith, G. J.
• Leyva, V.
• Marques, C.
• DeBeer-Schmitt, L.
• Kolesnikov, A. I.
• Zhao, Y.
• Lynn, J. W.
• Basov, D. N.
• Kotliar, G.
• Aronson, M. C.

Titel

Origin of the charge gap in LaMnPO

Ist Teil von

• Physical review. B, Condensed matter and materials physics, 2014-11, Vol.90 (18), Article 180403

Erscheinungsjahr

2014

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• We present high temperature inelastic neutron scattering and magnetic susceptibility measurements of the antiferromagnetic insulator LaMnPO that are consistent with the presence of two-dimensional magnetic correlations up to a temperature T sub(max) approximately 700 >> T sub(N) = 375K, the Neel temperature. Optical transmission measurements show the T = 300 K direct charge gap Delta = 1 eV has decreased only marginally by 500 K and suggest it decreases by only 10% at T sub(max). Density functional theory and dynamical mean-field theory calculations reproduce a direct charge gap in paramagnetic LaMnPO only when a strong Hund's coupling J sub(H) = 0.9eV is included, as well as on-site Hubbard U = 8 eV. Our results show that LaMnPO is a Mott-Hund's insulator, in which the charge gap is rather insensitive to antiferromagnetic exchange coupling.