Quasiparticle Interference of Spin-Triplet Superconductors: Application to UTe_{2}

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Quasiparticle interference (QPI) from scanning tunneling microscopy (STM) is crucial for determining the pairing symmetry of unconventional superconductors.
• Spin-triplet superconductors exhibit unique properties due to their multicomponent d-vector and topological surface states, differentiating them from spin-singlet counterparts.

Purpose of the Study:

• To investigate the general properties of QPI on spin-triplet superconductor surfaces.
• To compare computed QPI with experimental STM data for the spin-triplet candidate UTe2.
• To differentiate between candidate pairing instabilities (B2u and B3u) in UTe2 using QPI signatures.

Main Methods:

• Theoretical examination of QPI properties on spin-triplet superconductor surfaces.
• Development of a microscopic model for the spin-triplet candidate UTe2.
• Comparison of theoretical QPI calculations with experimental STM measurements.

Main Results:

• QPI on spin-triplet superconductors shows distinct features compared to spin-singlet ones, influenced by the d-vector and topological surface states.
• The study identified unique QPI intensity features for the B2u and B3u pairing instabilities in UTe2.
• Topological surface states, protected by chiral and mirror symmetries, offer further signatures for identifying the pairing symmetry.

Conclusions:

• QPI is a powerful tool for distinguishing between B2u and B3u pairing symmetries in UTe2.
• The interplay of spin-triplet pairing and topological surface states provides unique QPI signatures.
• Experimental STM measurements can effectively pinpoint the pairing symmetry channel in materials like UTe2.