Observation of vortices and hidden pseudogap from scanning tunneling spectroscopic studies of electron-doped cuprate superconductor $Sr_{0.9}La_{0.1}CuO_2$

TL;DR

This study reports the first observation of vortices in an electron-doped cuprate superconductor with a high transition temperature, revealing a hidden pseudogap and unconventional spectral behavior that challenge existing theories.

Contribution

It provides the first direct evidence of vortices and a hidden pseudogap in an electron-doped cuprate superconductor, expanding understanding of high-$T_c$ superconductivity.

Findings

Vortices observed in $Sr_{0.9}La_{0.1}CuO_2$ with $T_c$ of 43 K.

Detection of a hidden low-energy pseudogap inside vortex cores.

Spectral evolution with temperature and magnetic field is unconventional.

Abstract

We present the first demonstration of vortices in an electron-type cuprate superconductor, the highest $T_c$ (= 43 K) electron-type cuprate $Sr_{0.9}La_{0.1}CuO_2$. Our spatially resolved quasiparticle tunneling spectra reveal a hidden low-energy pseudogap inside the vortex core and unconventional spectral evolution with temperature and magnetic field. These results cannot be easily explained by the scenario of pure superconductivity in the ground state of high-$T_c$ superconductivity.