Revivification of the Concept of Coexisting CDDW and DSC Orders for Bi2212 | Chapter 7 | Newest Updates in Physical Science Research Vol. 6

 The Chiral d-density wave (CDDW or d+id) order, corresponding to the anti-ferromagnetic wave vector Q= (± (1− φ), ±φ),(±φ, ±(1−φ)) with φ ~ 0.2258 located roughly on the boundary of the Fermi pockets in the momentum space. is assumed to represent the pseudo-gap (PG) state of a Bilayer Bi2212 system- a cuprate superconductor. This system involves quasi-particle interlayer In Josephson junctions, tunnelling differs from Cooper pair tunnelling. Conjecturally, the dominating interaction connecting the quasiparticle pairs in the PG state is the same “superexchange” spin coupling that makes undoped cuprates antiferromagnetic. Mott insulators are a type of insulator that is used to keep The intra-layer d wave superconductivity (DSC) is thought to be caused by attractive interactions. The mean-field framework is used to present the full analysis. The gap equations are solved combined with the equation to determine the chemical potential in a self-consistent manner (applying Luttinger sum rule). In the absence of momentum-conserving inter-layer tunnelling, In the absence of momentum-conserving inter-layer tunnelling, Wyle/ Dirac semi-metal-like (narrow-gap direct semiconductor-like) situation in the confined region of the momentum space (MCIT). Because of the pseudo-Zeeman field created by inter-layer tunnelling, there is pseudo spin- momentum locking (PSML). The PSML observed appears to be a system-wide phenomenon in which the sign of the second neighbour has no bearing. Spin-band locking is discovered to be achievable in the limited region of momentum space in the presence of Rashba coupling and MCIT. Furthermore, in the quasi-particle excitation spectrum, the pseudoZeeman term leads to momentum space. Tunneling is a term used to describe the process of digging The CDDW and DSC are found to be two competing orders, as the former depletes the spectral weight available for pairing in the anti-nodal region of momentum space, while the latter does not. This contradicts a prepared pairing scenario and explains why we expected distinct structures for the pseudo-gap and superconducting gap. Furthermore, at energies greater than the gap energy, the spectral weight below Tc is depleted. This is an example of cuprates' strong-coupling superconductivity.

Author (s) Details

Dr. Partha Goswami
Deshbandhu College, University of Delhi, Kalkaji, New Delhi-110019, India.

Dr. U. P. Tyagi
Deshbandhu College, University of Delhi, Kalkaji, New Delhi-110019, India.

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