Feshbach resonances and mesoscopic phase separation near a quantum critical point in multiband FeAs-based superconductors

Abstract

High Tc superconductivity in FeAs-based multilayers (pnictides), evading temperature decoherence effects in a quantum condensate, is assigned to a Feshbach resonance (called also shape resonance) in the exchange-like interband pairing. The resonance is switched on by tuning the chemical potential at an electronic topological transition (ETT) near a band edge, where the Fermi surface topology of one of the subbands changes from 1D to 2D topology. We show that the tuning is realized by changing i) the misfit strain between the superconducting planes and the spacers ii) the charge density and iii) the disorder. The system is at the verge of a catastrophe i.e. near a structural and magnetic phase transition associated with the stripes (analogous to the 1/8 stripe phase in cuprates) order to disorder phase transition. Fine tuning of both the chemical potential and the disorder pushes the critical temperature Ts of this phase transition to zero giving a quantum critical point. Here the quantum lattice and magnetic fluctuations promote the Feshbach resonance of the exchange-like anisotropic pairing. This superconducting phase that resists to the attacks of temperature is shown to be controlled by the interplay of the hopping energy between stripes and the quantum fluctuations. The superconducting gaps in the multiple Fermi surface spots reported by the recent ARPES experiment of D. V. Evtushinsky et al. arXiv:0809.4455 are shown to support the Feshbach scenario.

31 pages, 7 figures

References in corpus (38)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Superconductivity in iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAs
• Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln=La,Nd)
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• Phase transitions in LaFeAsO: structural, magnetic, elastic, and transport properties, heat capacity and Mossbauer spectra
• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• Theory of magnetic excitations in iron-based layered superconductors
• First order structural phase transition in CaFe${}_2$As${}_2$
• Crystallographic Phase Transition and High-Tc Superconductivity in LaFeAsO:F
• Structural and magnetic phase transitions in the ternary iron arsenides SrFe2As2 and EuFe2As2
• Magnetic and structural transitions in layered FeAs systems: AFe2As2 versus RFeAsO compounds
• Momentum dependence of the superconducting gap in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
• Spin and Lattice Structure of Single Crystal SrFe2As2
• Structural transition and anisotropic properties of single crystalline SrFe2As2
• Strong coupling between magnetic and structural order parameters in SrFe2As2
• Magnetic Order of the Iron Spins in NdOFeAs
• Suppression of Magnetic Order by Pressure in BaFe2As2
• The effect of internal pressure on the tetragonal to monoclinic structural phase transition in ReOFeAs: the case of NdOFeAs
• Fermi Surface and Band Renormalization in (Sr,K)Fe${}_2$As${}_2$ Superconductor from Angle-Resolved Photoemission Spectroscopy
• Pressure-induced shift of T${}_c$ in K${}_x$Sr${}_{1-x}$Fe${}_2$As${}_2$ (x=0.2, 0.4, 0.7): Analogy to the high-T${}_c$ cuprate superconductors
• The Feshbach resonance and nanoscale phase separation in a polaron liquid near the quantum critical point for a polaron Wigner crystal
• Doping evolution of itinerant magnetic excitations in Fe-based oxypnictides
• Fermi surface and strong coupling superconductivity in single crystal NdFeAsO_{1-x}F_x

Cited by in corpus (5)

• From Majorana theory of atomic autoionization to Feshbach resonances in high temperature superconductors
• The Misfit Strain Critical Point in the 3D Phase Diagrams of Cuprates
• WDX-Analysis of the New Superconductors RO(1-x)F(x)FeAs and Its Consequences on the Electronic Phase Diagram
• The Microstrain-Doping Phase Diagram of the Iron Pnictides Heterostructures at Atomic Limit
• A model for liquid-striped liquid phase separation in liquids of anisotropic polarons