Visualization of spatial inhomogeneity in the superconducting gap using micro-ARPES

Abstract

Electronic inhomogeneity arises ubiquitously as a consequence of adjacent and/or competing multiple phases or orders in strongly correlated electron systems. Gap inhomogeneity in high-[Formula: see text] cuprate superconductors has been widely observed using scanning tunneling microscopy/spectroscopy. However, it has yet to be evaluated by angle-resolved photoemission spectroscopy (ARPES) due to the difficulty in achieving both high energy and spatial resolutions. Here, we employ high-resolution spatially-resolved ARPES with a micrometric beam (micro-ARPES) to reveal the spatial dependence of the antinodal electronic states in optimally-doped Bi[Formula: see text]Sr[Formula: see text]CaCu[Formula: see text]O[Formula: see text]. Detailed spectral lineshape analysis was extended to the spatial mapping dataset, enabling the identification of the spatial inhomogeneity of the superconducting gap and single-particle scattering rate at the micro-scale. Moreover, these physical parameters and their correlations were statistically evaluated. Our results suggest that high-resolution spatially-resolved ARPES holds promise for facilitating a data-driven approach to unraveling complexity and uncovering key parameters for the formulation of various physical properties of materials.

Keywords

• Angle-resolved photoemission spectroscopy (ARPES)
• spatially-resolved ARPES
• micro-ARPES
• gap inhomogeneity
• high- cuprates
• measurement informatics