Bipartite electronic superstructures in the vortex core of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$

TL;DR

This study uses spectroscopic-imaging STM to reveal how vortices in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ influence electronic superstructures, showing coexistence and competition between superconductivity and other electronic orders.

Contribution

It uncovers energy-dependent bipartite electronic superstructures in vortex cores, demonstrating how vortices amplify existing broken-spatial-symmetry patterns and generate vortex checkerboard patterns.

Findings

Vortices induce a vortex checkerboard in low-energy quasiparticles.

Vortices amplify preexisting broken-spatial-symmetry patterns at high energy.

Evidence of competition between superconductivity and other electronic orders.

Abstract

A magnetic field applied to type-II superconductors introduces quantized vortices that locally quench superconductivity, providing a unique opportunity to investigate electronic orders that may compete with superconductivity. This is especially true in cuprate superconductors in which mutual relationships among superconductivity, pseudogap, and broken-spatial-symmetry states have attracted much attention. Here we observe energy and momentum dependent bipartite electronic superstructures in the vortex core of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ using spectroscopic-imaging scanning tunneling microscopy (SI-STM). In the low-energy range where the nodal Bogoliubov quasiparticles are well-defined, we show that the quasiparticle scattering off vortices generates the electronic superstructure known as "vortex checkerboard". In the high-energy region where the pseudogap develops, vortices amplify the broken-spatial-symmetry patterns that preexist in zero field. These data reveal canonical d-wave superconductivity near the node, yet competition between superconductivity and broken-spatial-symmetry states near the antinode.