Universal spectral signatures in pnictides and cuprates: the role of quasiparticle-pair coupling. (3rd October 2017)

• Record Type: Journal Article
• Authors: Sacks, William; Mauger, Alain; Noat, Yves
• Is Part Of: Journal of physics. Volume 29:Number 44(2017)
• Publication Date: 2017-10-03
• Subjects: cuprates -- unconventional superconductivity -- iron-based superconductors -- pseudogap -- quasiparticle excitations; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa884a
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Understanding the physical properties of a large variety of high- T c superconductors (SC), the cuprate family as well as the more recent iron-based superconductors, is still a major challenge. In particular, these materials exhibit the 'peak-dip-hump' structure in the quasiparticle density of states (DOS). The origin of this structure is explained within our pair–pair interaction (PPI) model: The non-superconducting state consists of incoherent pairs, a 'Cooper-pair glass' which, due to the PPI, undergoes a Bose-like condensation below T c to the coherent SC state. We derive the equations of motion for the quasiparticle operators showing that the DOS 'peak-dip-hump' is caused by the coupling between quasiparticles and excited pair states, or 'super-quasiparticles'. The renormalized SC gap function becomes energy-dependent and non retarded, reproducing accurately the experimental spectra of both pnictides and cuprates, despite the large difference in gap value.