Visualizing Pair-breaking Scattering Interference in Bulk FeSe

Abstract

Spatially periodic modulations of the superconducting gap have been recently reported in diverse materials and are often attributed to pair density wave order. An alternative mechanism, termed pair-breaking scattering interference (PBSI), was proposed to produce gap modulations without finite-momentum pairing. Here we investigate signatures of PBSI in bulk FeSe using scanning tunneling microscopy with superconductive tips, enabling enhanced energy resolution and Josephson tunneling. Subsurface magnetic scatterers with Yu-Shiba-Rusinov states are identified in FeSe, around which we observe particle-hole symmetric gap modulations accompanied by spatial modulation of the Josephson current. Those modulations have wavevectors consistent with intra-pocket PBSI. We further demonstrate that phase-referenced quasiparticle interference imaging offers an independent and direct probe of PBSI beyond gap mapping. These results establish PBSI as a viable origin of gap modulations in superconductors lacking preexisting charge/spin density wave orders, and motivate further investigation of the intriguing gap modulation phenomenology.

4 figures

References in corpus (37)

• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• The Physics of Pair Density Waves
• Discovery of Orbital-Selective Cooper Pairing in FeSe
• Detection of a Cooper-Pair Density Wave in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$
• Topological superconductivity in monolayer transition metal dichalcogenides
• Magnetic-field Induced Pair Density Wave State in the Cuprate Vortex Halo
• The Fulde-Ferrell-Larkin-Ovchinnikov state for ultracold fermions in lattice and harmonic potentials: a review
• Discovery of a Cooper-Pair Density Wave State in a Transition-Metal Dichalcogenide
• Visualizing the Energy-gap Modulations of the Cuprate Pair Density Wave State
• Detection of a Pair Density Wave State in UTe${}_2$
• Discovery of a pair density wave state in a monolayer high-Tc iron-based superconductor
• Wave-function hybridization in Yu-Shiba-Rusinov dimers
• Chiral kagome superconductivity modulations with residual Fermi arcs in KV3Sb5 and CsV3Sb5
• Visualizing the periodic modulation of Cooper pairing in a severely underdoped cuprate
• Magnetic-field sensitive charge density wave orders in the superconducting phase of UTe2
• Smectic Pair Density Wave Order in EuRbFe4As4
• Spatially dispersing Yu-Shiba-Rusinov states in the unconventional superconductor ${\mathrm{FeTe}}_{0.55}{\mathrm{Se}}_{0.45}$
• Identification of a Nematic Pair Density Wave State in Bi2Sr2CaCu2O8+x
• Emergent superconductivity and pair density wave at antiphase boundaries of charge density wave order in kagome metals
• Particle-hole asymmetric superconducting coherence peaks in overdoped cuprates
• Imaging the Spatial Form of a Superconducting Order Parameter via Josephson Scanning Tunneling Spectroscopy
• Directly visualizing nematic superconductivity driven by the pair density wave in NbSe${}_2$
• Observation of superconducting pair density modulation within lattice unit cell
• Determination of the Superconducting Order Parameter from Defect Bound State Quasiparticle Interference
• Quarter Metal Superconductivity
• Pair-breaking scattering interference as a mechanism for superconducting gap modulation
• Atomic-scale Frustrated Josephson Coupling and Multi-condensate Visualization in FeSe
• Evidence for a robust sign-changing s-wave order parameter in monolayer films of superconducting Fe (Se,Te)/Bi2Te3
• Imaging half-unit-cell Cooper-pair density waves in monolayer 1T${}^{\prime }$-MoTe${}_2$
• High-Resolution Spectroscopy of the Intermediate Impurity States near a Quantum Phase Transition
• Discovery of smectic charge and pair-density-wave orders in topological monolayer 1T${}^{\prime }$-MoTe${}_2$
• Switchable chiral 2x2 pair density wave in pure CsV3Sb5
• Phase-sensitive evidence for pair density waves in a kagome superconductor
• Visualizing uniform lattice-scale pair density wave in single-layer FeSe/SrTiO3 films
• Intertwined charge and pair density orders in a monolayer high-Tc iron-based superconductor
• Josephson scanning tunneling spectroscopy in superconducting phases coexisting with pair-, charge- and spin-density-waves
• Distinct Modulation Behavior of Superconducting Coherence Peaks Associated with Sign-Reversal Gaps in FeTe${}_{0.55}$Se${}_{0.45}$