2025/12/01 by Zhiyong Hou, Hou, Zhiyong, Zhiyuan Shang +9
Materials Science · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Iron-based superconductors research #Organic and Molecular Conductors Research #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2512.01703
openalex publication_date 2025/12/01 · openalex created_date 2025/12/03 · openalex updated_date 2026/07/28
Using high-resolution scanning tunneling microscopy, we reveal two distinct types of superconducting (SC) gap modulations in bulk superconductor FeTe0.55Se0.45. By analyzing the phase relation between modulations at positive and negative bias, we identify in-phase (particle-hole asymmetric) and anti-phase (particle-hole symmetric) oscillations, corresponding to sign-reversing and sign-preserving scattering processes, respectively. The observed features are consistent with predictions from pair-breaking scattering interference (PBSI) theory and are distinguishable from other alternative mechanisms such as pair density waves. Our results provide compelling evidence that PBSI is the dominant mechanism behind the SC gap modulations in FeTe0.55Se0.45, offering new insights into the role of impurity scattering in iron-based superconductors.