The temperature dependence of the local tunnelling conductance in cuprate superconductors with competing AF order

TL;DR

This study models the temperature-dependent local tunnelling conductance in cuprate superconductors, revealing the coexistence and suppression of antiferromagnetic and superconducting orders, and comparing theoretical results with STM experiments.

Contribution

It introduces a $t-t'-U-V$ model to analyze temperature effects on local conductance and magnetic order in cuprates, highlighting the emergence of stripe and charge orders at higher temperatures.

Findings

Pure d-wave superconductivity dominates at low T near optimal doping.

Antiferromagnetic order with stripe modulation appears at higher T.

Calculated LDTC features align with recent STM experimental observations.

Abstract

Based on the $t-t'-U-V$ model with proper chosen parameters for describing the cuprate superconductors, it is found that near the optimal doping at low temperature ($T$), only the pure d-wave superconductivity ($d$SC) prevails and the antiferromagnetic (AF) order is completely suppressed. At higher $T$, the AF order with stripe modulation and the accompanying charge order may emerge, and they could exist above the $d$SC transition temperature. We calculate the local differential tunnelling conductance (LDTC) from the local density of states (LDOS) and show that their energy variations are rather different from each other as $T$ increases. Although the calculated modulation periodicity in the LDTC/LDOS and bias energy dependence of the Fourier amplitude of LDTC in the "pseudogap" region are in good agreement with the recent STM experiment [Vershinin $et al.$, Science {\bf 303}, 1995 (2004)], we point out that some of the energy dependent features in the LDTC do not represent the intrinsic characteristics of the sample.