Nature of the electronic states involved in the chemical bonding and superconductivity at high pressure in SnO
J. A. McLeod+, A. V. Lukoyanov*,**, E. Z. Kurmaev*, L. D. Finkelstein*, A. Moewes+
+Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon,
Saskatchewan S7N 5E2, Canada
*Institute of Metal Physics, Russian Academy of Sciences, Ural Division, 620990 Yekaterinburg, Russia
**Ural Federal University, 620002 Yekaterinburg, Russia
We have investigated the electronic structure and the Fermi surface
of SnO using density functional theory (DFT)
calculations within recently proposed exchange-correlation potential (PBE+mBJ)
at ambient conditions and high pressures up to 19.3 GPa where superconductivity
was observed. It was found that the Sn valence states
and 5d) are strongly hybridized with the O 2p-states,
and that our DFT-calculations are in good agreement with O K-edge X-ray
spectroscopy measurements for both occupied and empty states.
It was demonstrated that the metallic states appearing under pressure
in the semiconducting gap stem due to the transformation of the weakly
hybridized O 2p-Sn 5sp subband corresponding
to the lowest valence state of Sn in SnO.
We discuss the nature of the electronic states
involved in chemical bonding and formation of the hole and electron pockets
with nesting as a possible way to superconductivity.