Quasiparticle interference in multiband superconductors with strong coupling

Abstract

We develop a theory of the quasiparticle interference (QPI) in multiband superconductors based on strong-coupling Eliashberg approach within the Born approximation. In the framework of this theory, we study dependencies of the QPI response function in the multiband superconductors with nodeless s-wave superconductive order parameter. We pay a special attention to the difference of the quasiparticle scattering between the bands having the same and opposite signs of the order parameter. We show that, at the momentum values close to the momentum transfer between two bands, the energy dependence of the quasiparticle interference response function has three singularities. Two of these correspond to the values of the gap functions and the third one depends on both the gaps and the transfer momentum. We argue that only the singularity near the smallest band gap may be used as an universal tool to distinguish between $s_{++}$ and $s_{\pm }$ order parameters. The robustness of the sign of the response function peak near the smaller gap value, irrespective of the change in parameters, in both the symmetry cases is a promising feature that can be harnessed experimentally.

16 pages, 16 figures

References in corpus (46)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Superconductivity in Iron Compounds
• High-temperature superconductivity in iron-based materials
• A Common Thread: the pairing interaction for the unconventional superconductors
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Gap symmetry and structure of Fe-based superconductors
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Imaging Quasiparticle Interference in Bi2Sr2CaCu2O8+d
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Reply to Comment on "Unconventional s-wave superconductivity in Fe(Se,Te)"
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Two-gap superconductivity in MgB${}_2$: clean or dirty?
• Normal-State Spin Dynamics and Temperature-Dependent Spin Resonance Energy in an Optimally Doped Iron Arsenide Superconductor
• Periodic Density of States Modulations in Superconducting $\mathrm{B}{\mathrm{i}}_2\mathrm{S}{\mathrm{r}}_2\mathrm{CaC}{\mathrm{u}}_2{\mathrm{O}}_{8+\delta }$
• Competition and coexistence of antiferromagnetism and superconductivity in underdoped Ba(Fe0.953Co0.047)2As2
• Iron based superconductors: magnetism, superconductivity and electronic structure
• Iron based high transition temperature superconductors
• Satellites and large doping- and temperature-dependence of electronic properties in hole-doped BaFe2As2
• Quasi-particle interference and superconducting gap in a high-temperature superconductor Ca2-xNaxCuO2Cl2
• Using Gap Symmetry and Structure to Reveal the Pairing Mechanism in Fe-based Superconductors
• Universal heat conduction in the iron-arsenide superconductor KFe2As2 : Evidence of a d-wave state
• NMR relaxation rate in superconducting pnictides: extended $s_{\pm }$ scenario
• The wave-vector power spectrum of the local tunnelling density of states: ripples in a d-wave sea
• Disorder induced transition between s_+- and s_++ states in two-band superconductors
• Interband superconductivity: contrasts between BCS and Eliashberg theory
• Andreev spectra and subgap bound states in multiband superconductors
• Eliashberg approach to superconductivity-induced infrared anomalies in Ba0.68K0.32Fe2As2
• Possible phase-sensitive tests of pairing symmetry in pnictide superconductors
• Model for nodal quasiparticle scattering in a disordered vortex lattice
• Unexpected impact of magnetic disorder on multiband superconductivity
• Optical conductivity of iron-based superconductors
• Evidence of d-wave Superconductivity in K_(1-x)Na_xFe_2As_2 (x = 0, 0.1) Single Crystals from Low-Temperature Specific Heat Measurements
• Designing phase-sensitive tests for Fe-based superconductors
• Manifestation of impurity induced s_{+-} -> s_{++} transition: multiband model for dynamical response functions
• Tracing the $s_{\pm }$-symmetry in iron pnictides by controlled disorder
• Superconducting specific heat jump $\Delta C_{\mathrm{el}}\propto T_c^{\beta }(\beta \approx 2)$ for K${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$
• Quasiparticle interference in an iron-based superconductor
• The Josephson current in Fe-based superconducting junctions: theory and experiment
• Normal state resistivity of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: evidence for multiband strong-coupling behavior
• Transition from sign-reversed to sign-preserved Cooper-pairing symmetry in sulfur-doped iron selenide superconductors
• Superconducting properties of K${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$ under pressure
• Quasiparticle Interference in Fe-based Superconductors Based on a Five-Orbital Tight-Binding Model