Tunneling into clean Heavy Fermion Compounds: Origin of the Fano Lineshape

Abstract

Recently observed tunneling spectra on clean heavy fermion compounds show a lattice periodic Fano lineshape similar to what is observed in the case of tunneling to a Kondo ion adsorbed at the surface. We show that the translation symmetry of a clean surface in the case of \emph{weakly correlated} metals leads to a tunneling spectrum given by the superposition of the local weighted density of states of all energy bands involved, which does not have a Fano lineshape. In particular the spectrum will show any hybridization gap present in the band structure. By contrast, in a \emph{strongly correlated} heavy fermion metal the heavy quasiparticle states will be broadened by interaction effects. The broadening grows as one moves away from the Fermi surface, up to a value of the order of $T_K$, the Kondo scale. We show that the hybridization gap is completely filled in this way, and an ideal Fano lineshape of width $T_K$ results, similar to the impurity case. We also discuss the possible influence of the tunneling tip on the surface, in (i) leading to additional broadening of the Fano line, and (ii) enhancing the hybridization locally, hence adding to the impurity type behavior. The latter effects depend on the tip-surface distance.

4+ pages, 2 figs

References in corpus (8)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum Criticality in Heavy Fermion Metals
• Fractionalized Fermi liquids
• Imaging the Fano Lattice to 'Hidden Order' Transition in URu2Si2
• Electron Cotunneling into a Kondo Lattice
• Electron spin resonance in Kondo systems
• The Fano effect in the point contact spectroscopy of heavy electron materials
• Point-contact spectroscopy in heavy-fermion superconductors

Cited by in corpus (38)

• Colloquium: Hidden Order, Superconductivity, and Magnetism -- The Unsolved Case of URu2Si2
• Visualizing heavy fermions emerging in a quantum critical Kondo lattice
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Heavy-electron quantum criticality and single-particle spectroscopy
• Hybridization gap and Fano resonance in SmB${}_6$
• Observation of the hybridization gap and Fano resonance in the Kondo lattice URu2Si2
• Hybridization wave as the 'Hidden Order' in URu${}_2$Si${}_2$
• Two-Fluid Model for Heavy Electron Physics
• Orbital-selective Kondo-lattice and enigmatic f-electrons emerging from inside the antiferromagnetic phase of a heavy fermion
• Hidden Order Transition in URu2Si2 and the Emergence of a Coherent Kondo Lattice
• Finite-temperature spectra and quasiparticle interference in Kondo lattices: From light electrons to coherent heavy quasiparticles
• Zooming in on heavy fermions in Kondo lattice models
• Emergent Coherent Lattice Behavior in Kondo Nanosystems
• Theory of Scanning Tunneling Spectroscopy: from Kondo Impurities to Heavy Fermion Materials
• Quantum Engineered Kondo Lattices
• Local Electronic Structure and Fano Interference in Tunneling into a Kondo Hole System
• Pressure-Tuned Point-Contact Spectroscopy of URu2Si2 from Hidden Order to Antiferromagnetic States: Similarity of the Fermi Surface Gapping
• Two-channel point-contact tunneling theory of superconductors
• Planar tunneling spectroscopy of the topological Kondo insulator SmB${}_6$
• Local suppression of the hidden order phase by impurities in URu2Si2
• Charge density wave in hidden order state of URu${}_2$Si${}_2$
• Replicas of the Fano resonances induced by phonons in a subgap Andreev tunneling
• Hybridization gap in the heavy-fermion compound UPd${}_2$Al${}_3$ via quasiparticle scattering spectroscopy
• Spectroscopic Evidence for the Direct Involvement of Local Moments in the Pairing Process of the Heavy-Fermion Superconductor CeCoIn${}_5$
• Symplectic large-N theory of topological heavy-fermion semiconductors
• High temperature antiferromagnetism in Yb based heavy fermion systems proximate to a Kondo insulator
• Structural and electrical characterization of the monolayer Kondo-lattice compound CePt${}_6$/Pt(111)
• Scanning tunneling microscopy of adsorbed molecules on metalic surfaces for nearly localized atomic states
• The surface density of states of layered {\it f}-electron materials
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Origin of gap-like behaviors in URu${}_2$Si${}_2$: Combined study via quasiparticle scattering spectroscopy and resistivity measurements
• Coexisting Kondo hybridization and itinerant f-electron ferromagnetism in UGe2
• Recent Progress of Point Contact Spectroscopy as a Probe of Correlated Electron States
• Cotunneling into a Kondo lattice with odd hybridization
• Non-Zeeman splitting for a spin-resolved STM with a Kondo adatom in a spin-polarized two-dimensional electron gas
• Tunneling in heavy-fermion junctions
• Spatial interferences in the electron transport of heavy fermion materials
• Dimensionality effects in the LDOS of ferromagnetic hosts probed via STM: spin-polarized quantum beats and spin filtering