Particular type of gap in the spectrum of multiband superconductors
P. I. Arseev+*, S. O. Loiko+, N. K. Fedorov+
+P.N. Lebedev Physical Institute of RAS, 11991 Moscow, Russia
*National Research University, Higher School of Economics, 101000 Moscow, Russia
Abstract
We show, that in contrast to the free electron model (standard
BCS model), a particular gap in the
spectrum of multiband superconductors opens at some distance from the Fermi
energy, if conduction band is
composed of hybridized atomic orbitals of different symmetries. This gap has
composite
superconducting-hybridization origin, because it exists only if both the
superconductivity and the hybridization
between different kinds of orbitals are present. So for many classes of
superconductors with multiorbital
structure such spectrum changes should take place. These particular changes
in the spectrum at some distance
from the Fermi level result in slow convergence of the spectral weight of the
optical conductivity even in quite
conventional superconductors with isotropic s-wave pairing mechanism.