First-Principles Study of Kondo Insulator SmB6
M. Gmitraa, H. Čenčarikováb, P. Farkašovskýb
aUniversity of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
bInstitute of Experimental Physics SAS, Watsonova 47, 040 01 Košice, Slovakia
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We applied the Perdew-Burke-Ernzerhof hybrid functional (PBE0) within the density functional theory (DFT) to study electronic properties of the heavy fermion Kondo semiconductor SmB6. The calculation of the Hartee-Fock exchange contribution to the exact-exchange within the atomic sphere approximation for bulk SmB6 represents a computationally efficient, parameter-free method that provides good qualitative and quantitative agreement with photoemission experiments. Specifically, we found an energy difference of 7 eV between the occupied and unoccupied correlated Sm f states. Furthermore, the spin-orbit coupling yields a splitting of the occupied Sm f states of about 1 eV in agreement with recent angular resolved photoemission spectroscopy. The electronic spectrum in the vicinity of the X point shows a hybridization between the Sm 5d conduction band and the localized Sm 4f states at the Fermi level. This might lead to a transport gap opening.

DOI: 10.12693/APhysPolA.126.298
PACS numbers: 71.28.+d, 71.20.-b, 71.27.+a