https://doi.org/10.1007/s100510050260
Effect of electron correlation on superconducting pairing symmetry
1
Institute of Physics, Sachivalaya Marg,
Bhubaneswar 751 005, India
2
Instituto de Física, Universidade Federal Fluminense, Campus
da praia Vermelha, Av. Litornea s/n,
24210-340 Niterói Rio de Janeiro, Brazil
Corresponding author: a hng@if.uff.br
Received:
26
August
1997
Revised:
31
December
1997
Accepted:
28
January
1998
Published online: 15 April 1998
The role of electron correlation on
different pairing symmetries are discussed in details where the electron
correlation has been treated within the slave boson formalism.
It is shown that for a pure s or pure d wave pairing symmetry,
the electronic correlation suppresses the s wave gap magnitude
(as well as the Tc) at a faster rate than that for the d wave
gap. On the other hand, a complex order parameter of the form
(s+id) shows
anomalous temperature dependence. For example, if the temperature
(
) at
which the d wave component of the complex
order parameter vanishes happens to be
larger than that for the s wave component (
),
then the growth of the
d wave component is arrested with the onset of the s wave component of
the order parameter. In this mixed phase however, we find that
the suppression in different components of the gap as well as the
corresponding Tc due to coulomb correlation
are very sensitive to the relative pairing strengths
of s and d channels as well as the underlying lattice.
Interestingly enough, in such a scenario
(for a case of 
)
the gap magnitude of the d wave component increases with electron
correlation but not for certain
values of electron correlation.
However, this never happens in case of the
s wave component.
We also calculate the temperature dependence of the
superconducting gap along both the
high symmetry directions
( 
and 
) in a mixed
(s+id) symmetry pairing state
and the thermal variation
of the gap anisotropy
with electron correlation. The results are discussed
with reference to experimental observations.
PACS: 74.25.Dw – Superconductivity phase diagrams / 74.62.-c – Transition temperature variations / 74.20.Fg – BCS theory and its development
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998
