6 research outputs found
Pairing symmetry and long range pair potential in a weak coupling theory of superconductivity
We study the superconducting phase with two component order parameter
scenario, such as, , where . We show, that in absence of orthorhombocity, the usual
does not mix with usual symmetry gap in an anisotropic band
structure. But the symmetry does mix with the usual d-wave for . The d-wave symmetry with higher harmonics present in it also mixes with
higher order extended wave symmetry. The required pair potential to obtain
higher anisotropic and extended s-wave symmetries, is derived by
considering longer ranged two-body attractive potential in the spirit of tight
binding lattice. We demonstrate that the dominant pairing symmetry changes
drastically from to like as the attractive pair potential is obtained
from longer ranged interaction. More specifically, a typical length scale of
interaction , which could be even/odd multiples of lattice spacing leads
to predominant wave symmetry. The role of long range interaction on
pairing symmetry has further been emphasized by studying the typical interplay
in the temperature dependencies of these higher order and wave pairing
symmetries.Comment: Revtex 8 pages, 7 figures embeded in the text, To appear in PR
Effect of Interband Transitions on the c axis Penetration Depth of Layered Superconductors
The electromagnetic response of a system with two planes per unit cell
involves, in addition to the usual intraband contribution, an added interband
term. These transitions affect the temperature dependence and the magnitude of
the zero temperature c-axis penetration depth. When the interplane hopping is
sufficiently small, the interband transitions dominate the low temperature
behaviour of the penetration depth which then does not reflect the linear
temperature dependence of the intraband term and in comparison becomes quite
flat even for a d-wave gap. It is in this regime that the pseudogap was found
in our previous normal state calculations of the c-axis conductivity, and the
effects are connected.Comment: 8 pages, 5 figure
Determination of the crystal field splitting energy in Cd3As2 using magnetooptics
International audienc
Magneto-optical evidence of the topological phase transition in (111)-Pb 1-x Sn x Te
International audienc
Space charge mediated negative differential resistance in terahertz quantum well detectors
In terahertz quantum well infrared photodetectors, a built-in-charge- mediated regime transition of the electronic transport is thoroughly investigated. The very strong current discontinuity and negative differential resistivity behavior are explained in terms of band structure reorganizations. The analysis of bias versus current measurements reveals that the transition occurs when the first two wells of the structure become partially drained, and the second well enters the ionized regime before the first one. Both many-body effects and a careful model of the contact have to be considered to account for these features. The source of the built-in charge is identified as intersubband impact ionization. The regime transition is one of its few experimental proofs, and provides an original approach to investigate hot electron kinetics in multi-quantum-well structures. \ua9 2011 American Institute of Physics.Peer reviewed: YesNRC publication: Ye