V. V. Val'kov, D. M. Dzebisashvili, A. F. Barabanov, “Spin-polaron nature of fermion quasiparticles and their <nobr>$d$</nobr>-wave pairing in cuprate superconductors”, Pis'ma v Zh. Èksper. Teoret. Fiz., 2016, Volume 104, Issue 10,Pages <nobr>745

This article is cited in 7 papers

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Spin-polaron nature of fermion quasiparticles and their $d$-wave pairing in cuprate superconductors

V. V. Val'kov^a, D. M. Dzebisashvili^a, A. F. Barabanov^b

^a Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, Russia
^b Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia

Abstract: In the framework of the spin-fermion model, to which the Emery model is reduced in the limit of strong electron correlations, it is shown that the fermion quasiparticles in cuprate high-$T_c$ superconductors (HTSCs) arise under a strong effect of exchange coupling between oxygen holes and spins of copper ions. This underlies the spin-polaron nature of fermion quasiparticles in cuprate HTSCs. The Cooper instability with respect to the $d$-wave symmetry of the order parameter is revealed for an ensemble of such quasiparticles. For the normal phase, the spin-polaron concept allows us to reproduce the fine details in the evolution of the Fermi surface with the changes in the doping level $x$ observed in experiment for La$_{2-x}$Sr$_x$CuO$_4$. The calculated $T-x$ phase diagram correlates well with the available experimental data for cuprate HTSCs.

Received: 11.10.2016

DOI: 10.7868/S0370274X16220148