Pseudogap state in slightly doped by aluminium and praseodymium YBa$_2$Cu$_3$O$_{7-\delta}$ single crystals with a given topology of plane defects

TL;DR

This study investigates the pseudogap state in slightly Al and Pr doped YBa2Cu3O7−δ single crystals, revealing a specific temperature dependence of excess conductivity and describing the pseudogap via the BCS-BEC crossover model.

Contribution

It provides new insights into the pseudogap behavior in doped YBa2Cu3O7−δ crystals with a focus on the topology of plane defects and their impact on conductivity.

Findings

Excess conductivity follows a specific temperature dependence in the pseudogap regime.

The pseudogap temperature dependence aligns with the BCS-BEC crossover model.

Doping with Al and Pr affects the pseudogap and conductivity properties.

Abstract

In present work the conductivity in the basis plane of YBaCuO single crystals slightly doped by Al and Pr with a pre-specified topology of twin boundaries has been investigated. The excess conductivity for the analyzed samples shows dependence like $\Delta\sigma\sim(1-T/T^*)\exp(\Delta_{ab}^*/T)$ in wide temperature range $T_f<T<T^*$, where $T^*$ can be represents as mean field temperature of superconducting transition. The temperature dependence of pseudogap can be satisfactory described in terms of the BCS-BEC crossover theoretical model.