Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Origin of the Charge Gap in LaMnPO



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


We present inelastic neutron scattering and magnetization measurements of the antiferromagnetic insulator LaMnPO that are well described by a Heisenberg spin model. These measurements are consistent with the presence of two-dimensional magnetic correlations up to a temperature Τmax approximately equal} 700K >> ΤN = 375 K, the Neel temperature. Optical transmission measurements show the Τ=300 K direct charge gap Δ} = 1eV has decreased by only 10% at Τmax. Density functional theory and dynamical mean field theory calculations reproduce a direct charge gap in paramagnetic LaMnPO only when a strong Hund's coupling JH = 0.9 eV is included, as well as onsite Hubbard U = 8 eV. These results show the direct charge gap in LaMnPO is rather insensitive to antiferromagnetic exchange coupling and instead is a result of the local physics governed by U and JH.
Physical Review B


Antiferromagnet (375 K), Insulator, Spin dynamics, Inelastic Neutron Scattering, Density functional theory, Hund's coupling, Hubbard U


McNally, D. , Simonson, J. , Post, K. , Yin, Z. , Pezzoli, M. , Smith, G. , Leyva, V. , Marques, C. , DeBeer-Schmitt, L. , Kolesnikov, A. , Zhao, Y. , Lynn, J. , Basov, D. , Kotliar, G. and Aronson, M. (2014), Origin of the Charge Gap in LaMnPO, Physical Review B, [online], (Accessed May 20, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created November 17, 2014, Updated October 12, 2021