Possible Pairing Symmetry in the FeSe-Based Superconductors Determined by Quasiparticle Interference

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Quasiparticle interference (QPI) is a powerful technique for probing electronic structures.
• Determining the pairing symmetry in superconductors like FeSe is crucial for understanding superconductivity.

Purpose of the Study:

• To investigate momentum-integrated QPI in FeSe-based superconductors.
• To provide an alternative interpretation of experimental data regarding pairing symmetry.

Main Methods:

• Theoretical analysis of momentum-integrated QPI.
• Experimental data analysis of FeSe-based superconductors.

Main Results:

• The study demonstrates that including incipient bands and superconducting (SC) pairing can accurately fit experimental bound states and QPI.
• This fit is achievable even without sign changes in the SC order parameter on the Fermi surfaces.

Conclusions:

• An alternative explanation for experimental observations in FeSe superconductors is proposed.
• Further careful identification of pairing symmetry is necessary for understanding the pairing mechanism.