The Origin of an Inflection Point on the Temperature Dependence of the London Penetration Depth in Hole-Doped Cuprate High-Temperature Superconductors

https://doi.org/10.1134/S1063776121080021

A scenario of the formation of an experimentally observed inflection point on the temperature dependence of the London penetration depth λ in cuprate high-temperature superconductors (HTSCs) with optimal hole doping is discussed within the spin-polaron concept. It is shown that the reason for the appearance of an inflection point on the 1/λ²(T) dependence is due to the features of the energy spectrum of spin-polaron quasiparticles in the superconducting phase, as well as to the specific temperature dependence of their spectral density.