Multiband Model of Cuprate Superconductivity

Abstract

A minimal model for the description of cuprate superconductor characteristics on doping scale (hole and electron) is developed. The leading interband pairing channel couples an itinerant band and defect states created by doping. Bare gaps between them are supposed and become closed by extended doping. Band overlap conditions determine special points in the phase diagram. Nodal and antinodal momentum regions are distinguished. Illustrative calculations have been made using a mean-field pair-transfer multiband Hamiltonian and corresponding free-energy expansions. The results are self-consistent and demonstrate that the elaborated approach is able to reproduce characteristic features of cuprate superconductors as, e.g., the doping dependence of Tc, superconducting gaps and pseudogaps, supercarrier density and effective mass, coherence length and penetration depth, critical magnetic fields and some other properties. Interband pairing scheme is suggested to be an essential aspect of cuprate superconductivity.

Interband superconductivity in spin-polarized subbands

“…2 and 3 by the zero-temperature gap equation solutions d 0 . The dome-type dependence d 0 (l) is common for two-band superconductivity [21] We can see that in general, depending on the efficiency of the pairing, the system can show besides pure normal and superconducting states also inclined metastable states as sketched in Fig. 8.…”

The Road Map toward Room-Temperature Superconductivity: Manipulating Different Pairing Channels in Systems Composed of Multiple Electronic Components

“…In cuprates it has been confirmed that multiple electronic components are involved in the pairing from penetration depth [31,32], ARPES [33,34], gap-to-TC ratio [35], the doping-dependent isotope effect [36][37][38][39] measurements, and the interband exchange interaction has been put forward to play a crucial role in enhancing TC, as well as in explaining these key experiments [36][37][38][39][40][41]. Therefore, the recipe to realize stable room temperature superconductivity has been suggested for complex systems composed of two different electronic components where instabilities are avoided [27][28][29][36][37][38] through the interactions between them, the polaronic component and the free particles, contributing to a single superconducting phase.…”

Interband Nodal-Region Pairing And the Antinodal Pseudogap in Hole Doped Cuprates

“…In fact, numerous direct and indirect experimental and theoretical results crowned by the observation of two SCG-s [6] positione the cuprates into the class of multigap superconductors with a multiband superconductivity mechanism. We refer here to the reviews [25][26][27][28] and some recent theoretical approaches [29][30][31][32][33][34][35][36][37]. Authors multiband approaches to cuprate superconductivity are based on the nonrigid nature of the electron spectrum reorganized by the necessary doping [35][36][37][38][39][40].…”