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Abstracts
P2.19
Some applications of a framework comprising
E
F
-incorporated
equations for
∆
0
and
T
c
and the corresponding number equations
Malik Gulshan
Jawaharlal Nehru University, Theory Group, School of Environmental Sciences,
New Delhi 110067, India
Augmenting the conventionally employed framework of BCS-BEC crossover
physicse.g.,
1
−
3
via inclusion of the equation for Tc and the corresponding
number equation, replacing the BCS equations for ∆
0
and
T
c
by the generalized
BCS equations when dealing with non-elemental superconductors (SCs), and
curtailing the limits of the number equations to avoid complex-valued solutions
when EF
k
B
θ
D
(
k
B
=Boltzmann constant;
θ
D
=Debye temperature), we draw
attention to recent work that dealt with (1) crossover physics without appeal to
scattering length theory,
4
(2) the long-standing puzzle posed by
SrT iO
3
,
5
(3) an
explanation of hitherto unexplained features of
La
2
CuO
4
,
6
and (4) heavy-fermion
SCs.
7
[1
.
] D.M. Eagles, Phys. Rev. 186, 456 (1969)
[2
.
] A.J. Leggett, in Modern Trends in the Theory of Condensed Matter (Springer-
Verlag, Berlin, 1980) p. 13
[3
.
] R.M. Quick, C. Eseberg,
M.deLlano, Phys. Rev. B 47, 11512 (1993)
[4
.
] G.P. Malik, IJMPB 28, 1450054 (2014)
[5
.
] G.P. Malik, IJMPB 28, 1450238 (2014)
[6
.
] G.P. Malik, V.S. Varma, World J. Condens. Matt. Phys. 5, 148 (2015)
[7
.
] G.P. Malik, J. Mod. Phys. 6, 1233 (2015)
P2.20
On the role of Fermi energy in determining properties of
superconductors
Malik Gulshan
Jawaharlal nehru University, Theory Group, School of Environmental Sciences,
New Delhi 110067, India
Supplementing the
E
F
-incorporated equations for ∆0 and
T
c
,1 which were
recently employed to deal with SrTiO3, La2CuO4, and heavy-fermion
superconductors (SCs), by similar equations for the critical current density
j
0
, we present new equations for the
j
0
of elemental and composite SCs that
depend solely on their following properties:
E
F
, Debye temperature, gram-atomic
volume, Sommerfeld constant, and a dimensionless construct where m* is the
effective mass of superconducting electrons and
P
0
their critical momentum.
Calling attention to the recent treatment of several SCs in such a framework,
2
we present here an explanation of the
{
T
c
, j
0
}
data on NbN films reported by
Semenov et al.
3
[1
.
] G.P. Malik (Author), Superconductivity: A New Approach Based on
the Bethe-Salpeter Equation in the Mean-Field Approximation, in: Series on
Directions in Condensed Matter Physics – Volume 21, World Scientific,Singapore,
2016
[2
.
] G.P. Malik, “On the role of Fermi energy in determining properties of
superconductors: A detailed comparative study of two elemental superconductors
(Sn and Pb), a non-cuprates (MgB2) and three cuprates (YBCO, Bi-2212, and
Tl-2212” (submitted)
[3
.
] A. Semenov et al., Phys. Rev. B 80, 054510 (2009)
64