Formation of Fermi Arcs at T $$ \ll $$ Tc in the Vicinity of d-Wave Nodes of Structurally Inhomogeneous YBa2Cu3O6.92 HTSCs

Meissner effect and structural inhomogeneity in HTSC YBa-=SUB=-2-=/SUB=-Cu-=SUB=-3-=/SUB=-O-=SUB=-6.92-=/SUB=-

“…As was shown in [3], in structurally heterogeneous HTSC samples, the superconducting gap is suppressed not only at nodal points (as it should be in ideal d-superconductors), but also near nodes. And this effect owes its existence to the depairing mechanism, which is present in the samples due to partial structural disordering.…”

“…In our work [3], a small review was given containing the results of X-ray data for the samples under consideration, as well as structural characteristics (including the parameters of elementary cells) and magnetic properties, both in variable and permanent magnetic fields.…”

“…In the work [3], special attention was paid to the existence of a temperature-linear contribution to the heat capacity proportional to ∼ (γ(0)T ). Such a contribution to the temperature dependence of the heat capacity is a contribution of a metallic type, which should not be in superconductors with an ideal crystal structure, but at the same time its presence (with different values) is recorded in all works by other authors in which the low-temperature heat capacity of HTSC of this composition was studied (Fig.…”

“…In our recent work [3] it was shown that, depending on the degree of structural heterogeneity, the gap near the nodes turns out to be zero not only in the nodes themselves, but also in their vicinity. The more pronounced the structural heterogeneity, the larger areas of the Fermi surface near nodes (nodal points) are not covered by a superconducting gap.…”

“…In this paper, the study is carried out on three polycrystalline samples of the composition YBa 2 Cu 3 O 6.92 , considered in our previous works, having close values of the temperatures of the superconducting transition T c from 90.8 K to 91.9 K, but differing in the sizes of crystallites, the degree of controlled structural disordering, and, as it turned out, the sizes of Fermi arcs in the vicinity of d-wave nodes [3].…”