Influence of Uniform Compression on the Temperature Dependence of the Pseudogap of Medium-Praseodymium-Doped Y1\u2212xPrxBa2Cu3O7\u2212\u03b4 Single Crystals

G Ya Khadzhai,S N Kamchatnaya,N R Vovk,A Chroneos,A L Chikina,Ι L Goulatis,R V Vovk

doi:10.1007/s10909-021-02590-y

Abstract

The effect of high pressure on the conductivity in the basal plane of HTSC single crystals of Y0.77Pr0.23Ba2Cu3O7−δ is investigated. It has been established that the excess conductivity, Δσ(T), of these single crystals in a wide temperature range Tf < T < T* can be described by an exponential temperature dependence. The description of the excess conductivity using the relation Δσ ~ (1 − T/T*)exp(Δ*ab/T) can be interpreted in terms of the mean-field theory, where T* is represented as the temperature pseudogap opening, and the temperature dependence of the pseudogap (PG) is satisfactorily described in the framework of the BCS-BEC crossover theory. An increase in the applied pressure leads to the effect of narrowing the temperature interval for the realization of the PG-regime, thereby expanding the region of the linear dependence ρ(T) in the ab-plane.

Highlights

The study of the pseudogap anomaly continues to be one of the main directions of high-temperature superconductivity (HTSC) physics [1,2,3]
Among the theoretical works supporting the first point of view is the crossover theory from the Bardeen–Cooper–Schrieffer (BCS) mechanism to the Bose–Einstein condensation (BEC) mechanism [11], in which the temperature dependencies of the pseudogap were obtained for the case of weak and strong pairing
In the present study we investigate the effect of high hydrostatic pressure up to 11 kbar on the temperature dependence of the pseudogap in Y 1−xPrxBa2Cu3O7−δ single crystals with an average (x≈0.23) concentration of praseodymium at temperatures far from the critical temperature (T > > Tc)

Summary

Introduction

The study of the pseudogap anomaly (decrease in the density of states) continues to be one of the main directions of high-temperature superconductivity (HTSC) physics [1,2,3]. Among the theoretical works supporting the first point of view is the crossover theory from the Bardeen–Cooper–Schrieffer (BCS) mechanism to the Bose–Einstein condensation (BEC) mechanism [11], in which the temperature dependencies of the pseudogap were obtained for the case of weak and strong pairing. These dependencies are described by equation: Δ(T ) = Δ(0) − T Δ(0) exp Δ(0) T × ⎡ ⎢ ⎢⎢1 ⎢⎣ +

Methods

Results

Conclusion