Nanoscale electronic inhomogeneity in FeSe${}_{0.4}$Te${}_{0.6}$ revealed through unsupervised machine learning

Abstract

We report on an apparent low-energy nanoscale electronic inhomogeneity in FeSe${}_{0.4}$Te${}_{0.6}$ due to the distribution of selenium and tellurium atoms revealed through unsupervised machine learning. Through an unsupervised clustering algorithm, characteristic spectra of selenium- and tellurium-rich regions are identified. The inhomogeneity linked to these spectra can clearly be traced in the differential conductance and is detected both at energy scales of a few electron volts as well as within a few millielectronvolts of the Fermi energy. By comparison with ARPES, this inhomogeneity can be linked to an electron-like band just above the Fermi energy. It is directly correlated with the local distribution of selenium and tellurium. There is no clear correlation with the magnitude of the superconducting gap, however the height of the coherence peaks shows significant correlation with the intensity with which this band is detected, and hence with the local chemical composition.

arXiv comment5 pages, 4 figures

References in corpus (16)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Evidence for Majorana bound state in an iron-based superconductor
• Observation of topological superconductivity on the surface of an iron-based superconductor
• Reply to Comment on "Unconventional s-wave superconductivity in Fe(Se,Te)"
• Zero-energy vortex bound state in the superconducting topological surface state of Fe(Se,Te)
• Strong electron correlations in the normal state of FeSe0.42Te0.58
• Physical properties of FeSe${}_{0.5}$Te${}_{0.5}$ single crystals grown under different conditions
• Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
• Superconductivity vs bound state formation in a two-band superconductor with small Fermi energy -- applications to Fe-pnictides/chalcogenides and doped SrTiO3
• The cleavage surface of the BaFe_(2-x)Co_(x)As_(2) and Fe_(y)Se_(1-x)Te_(x) superconductors: from diversity to simplicity
• A strongly inhomogeneous superfluid in an iron-based superconductor
• Imaging atomic-scale effects of high-energy ion irradiation on superconductivity and vortex pinning in Fe(Se,Te)
• Spatial Inhomogeneity of the Superconducting Gap and Order Parameter in FeSe_{0.4}Te_{0.6}
• Evidence for Orbital Order and its Relation to Superconductivity in FeSe0.4Te0.6
• Imaging the Real Space Structure of the Spin Fluctuations in an Iron-based superconductor
• Atomic-scale coexistence of short-range magnetic order and superconductivity in Fe${}_{1+y}$Se${}_{0.1}$Te${}_{0.9}$

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