Strong electron-phonon coupling in Ba${}_{1-x}$Sr${}_x$Ni${}_2$As${}_2$

Abstract

The charge density wave (CDW) or nematicity has been found to coexist with superconductivity in many systems. It is thus interesting that the superconducting transition temperature $T_c$ in the doped BaNi${}_2$As${}_2$ system can be enhanced up to six times as the CDW or nematicity in the undoped compound is suppressed. Here we show that the transverse acoustic phonons of Ba${}_{1-x}$Sr${}_x$Ni${}_2$As${}_2$ are strongly damped in a wide doping range and over the whole $Q$ range, which excludes its origin from either CDW or nematicity. The damping of TA phonons can be understood as large electron-phonon coupling and possible strong hybridization between acoustic and optical phonons as shown by the first-principle calculations. The superconductivity can be quantitatively reproduced by the change of electron-phonon coupling constant calculated by the McMillan equation in the BCS framework, which suggests that no quantum fluctuations of any order is needed to promote the superconductivity. On the contrary, the change of $T_c$ in this system should be understood as the six-fold suppression of superconductivity in undoped compounds.

8 pages, 4 figures

References in corpus (56)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phonons and related properties of extended systems from density-functional perturbation theory
• Electronic Liquid Crystal Phases of a Doped Mott Insulator
• Nematic order in iron superconductors - who is in the driver's seat?
• Theory of Intertwined Orders in High Temperature Superconductors
• Superconductivity in Cu_xTiSe_2
• The virtual crystal approximation revisited: Application to dielectric and piezoelectric properties of perovskites
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Divergent nematic susceptibility in an iron arsenide superconductor
• Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor
• Electronic liquid crystal state in the high-temperature superconductor YBCO(6.45)
• Electronic crystals: an experimental overview
• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Extended Phonon Collapse and the Origin of the Charge-Density-Wave in NbSe${}_2$
• Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
• Enhancement of superconductivity near a nematic quantum critical point
• Are non-Fermi-liquids stable to Cooper pairing?
• Thermodynamic evidence for nematic phase transition at the onset of pseudogap in YBa${}_2$Cu${}_3$O${}_y$
• Nematic quantum critical point without magnetism in FeSe1-xSx superconductors
• Superconductivity and non-Fermi liquid behavior near a nematic quantum critical point
• Intertwined vestigial order in quantum materials: nematicity and beyond
• Concepts relating magnetic interactions, intertwined electronic orders and strongly correlated superconductivity
• Observation of incipient charge nematicity in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Nematic susceptibility of hole- and electron-doped BaFe2As2 iron-based superconductors from shear modulus measurements
• Tuning the Charge Density Wave and Superconductivity in CuxTaS2
• First Order Phase Transition and Superconductivity in BaNi2As2 Single Crystals
• Superconductivity in SrNi2As2 Single Crystals
• Pseudogap temperature $T^{\star }$ of cuprate superconductors from the Nernst effect
• Structure and Anisotropic Properties of BaFe2-xNixAs2 (x = 0, 1, 2) Single Crystals
• Nature of charge density waves and superconductivity in 1\emph{T}-TaSe${}_{2-x}$Te${}_x$
• Disorder suppressed charge-density-wave and its origin in 1T-TaSe2-xTex
• Density functional study of BaNi${}_2$As${}_2$: Electronic structure, phonons and electron-phonon superconductivity
• Two types of nematicity in the phase diagram of the cuprate superconductor YBa${}_2$Cu${}_3$O${}_y$
• Giant Phonon Softening and Enhancement of Superconductivity by Phosphorus Doping of BaNi2As2
• Sixfold enhancement of superconductivity in a tunable electronic nematic system
• An inelastic x-ray study of phonon broadening and charge density wave formation in ortho-II ordered YBa2Cu3O6.54
• Diagonal Nematicity in the Pseudogap Phase of HgBa${}_2$CuO${}_{4+\delta }$
• The emergence of superconductivity in BaNi2(Ge1-xPx)2 at a structural instability
• Nematic Fluctuations in the Cuprate Superconductor Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$
• Divergent nematic susceptibility near the pseudogap critical point in a cuprate superconductor
• Incommensurate phonon anomaly and the nature of charge density waves in cuprates
• Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Unified phase diagram for iron-based superconductors
• Nematic Quantum Critical Fluctuations in BaFe${}_{2-x}$Ni${}_x$As${}_2$
• Multiple charge density waves and superconductivity nucleation at antiphase domain walls in the nematic pnictide Ba${}_{1-x}$Sr${}_x$Ni${}_2$As${}_2$
• An Electronic Nematic Liquid in BaNi${}_2$As${}_2$
• Elastoresistivity in the incommensurate charge density wave phase of BaNi${}_{\text{2}}$(As${}_{\text{1-x}}$P${}_{\text{x}}$)${}_{\text{2}}$
• Soft-phonon and charge-density-wave formation in nematic BaNi${}_2$As${}_2$
• Rotational symmetry breaking at the incommensurate charge-density-wave transition in Ba(Ni,Co)${}_2$(As,P)${}_2$: Possible nematic phase induced by charge/orbital fluctuations
• Nematic correlation length in iron-based superconductors probed by inelastic x-ray scattering
• Phonon softening and slowing down of charge-density-wave fluctuations in BaNi${}_2$As${}_2$
• Soft phonons reveal the nematic correlation length in Ba(Fe${}_{0.94}$Co${}_{0.06}$)${}_2$As${}_2$
• Dynamic spin-lattice coupling and nematic fluctuations in NaFeAs
• Evolution of Structure and Superconductivity in Ba(Ni${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Potential Lifshitz transition at optimal substitution in nematic pnictide Ba${}_{1-x}$Sr${}_x$Ni${}_2$As${}_2$
• Tracking the nematicity in cuprate superconductors: a resistivity study under uniaxial pressure

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