Intrinsic tunneling spectra of Bi_2(Sr_{2-x}La_x)CuO_6

TL;DR

This study measures intrinsic tunneling spectra in La-doped Bi2201 cuprates, revealing a similar pseudogap temperature despite different critical temperatures and spectral scales, with prominent pseudogap humps in the spectra.

Contribution

It provides new insights into the pseudogap behavior in Bi2201-La_x, showing a universal pseudogap temperature and detailed spectral features.

Findings

Pseudogap vanishes at T* ≈ 230-300K in both compounds.

Pseudogap humps appear as sharp peaks dominating spectra.

Similar pseudogap temperature despite different T_c and spectral scales.

Abstract

We have measured intrinsic-tunneling spectra of a single CuO-layer La-doped Bi_2Sr_{2-x}La_xCuO_{6+\delta} (Bi2201-La_x). Despite a difference of a factor of three in the optimal superconducting critical temperatures for Bi2201-La_{0.4} and Bi2212 (32 and 95 K, respectively) and different spectral energy scales, we find that the pseudogap vanishes at a similar characteristic temperature T*\approx 230-300K for both compounds. We find also that in Bi2201-La_x, PG humps are seen as sharp peaks and, in fact, even dominate the intrinsic spectra.