Mixeds-wave andd-wave superconductivity in high-Tcsystems

Phase transition from a dx2−y2 to dx2−y2+idxy superconductor

“…There are experimental evidences based on Josephson supercurrent for tunneling between Pb and YBa 2 Cu 3 O 7 (YBCO) [16], and on photoemission studies on Bi 2 Sr 2 CaCu 2 O 8+x [17] among others which are difficult to reconcile employing a pure s-or d-wave order parameter. These observations suggest that a mixed [s + exp(iθ)d] symmetry is applicable in these cases [18,19].…”

Ginzburg–Landau theory of Josephson field effect transistors

“…The GL theory has the identical form for the two cases [14]. Thus the actual microscopic mechanism of high-T c superconductivity doesn't affect our results.…”

“…The above choice has been tested in the succesful fitting or prediction of several quantities (calculation of the order parameter, NMR studies, specific heat etc.) [14,15].…”

Mesoscopic phase separation in anisotropic superconductors

“…To write down an explicit expression for the single-particle dispersion ω(k), one usually resorts to the tight-binding approximation [25,39,40,45], in which for a square lattice, one has…”

“…The majority of experiments evidence the existence of the mixed s + d pairing in cuprates [25,[30][31][32][33][34][35][36][37][38]. Several theoretical models, blending s-wave and d-wave features, describe the s + d superconducting gap state and provide a reasonable explanation for various experiments [39][40][41][42][43][44][45][46][47][48][49][50][51][52]. Thus, the occurrence of anisotropy in the gap of high-temperature cuprate superconductors seems to be well established.…”