2012/07/02 by Hsuan‐Hao Fan, C. S. Liu, Fan, Hsuan-Hao +3
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.1207.0270
openalex publication_date 2012/07/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by a recent experiment of Song et al. [Science \bf 332, 1410 (2011)], we theoretically study the spin dynamics, charge dynamics, and point-contact Andreev-reflection spectroscopy (PCARS) of two-band iron-based superconductors of a possible extended s_±-wave pairing symmetry. We consider the case of a dominant s_± gap blended by a secondary extended s component in which gap nodes can develop in the Fermi pockets near zone corner and/or boundary. Due to the strong nesting effect associated with nodal regions, dynamical spin and charge susceptibilities can exhibit strong peaks at momenta near (±π/2,0), (±π,±π/2), as well as (±π,0) in the unfolded Brillouin zone. For PCARS, considering an anisotropic band effect induced by an applied voltage, [100] differential conductance can exhibit a V-shape behavior manifesting a gap node occurring in such direction. It is highly suggested that the above features can be experimentally investigated to help sorting out the pairing symmetry of iron-based superconductors.