Spin-phonon coupling and pressure effect in the superconductor LiFeAs : Lattice dynamics from first-principles calculations

Abstract

The lattice dynamics and the effect of pressure on superconducting LiFeAs in both nonmagnetic (NM) and striped antiferromagnetic (SAF) phases are investigated using the plane-wave pseudopotential, density-functional-based method. While the obtained electron-phonon coupling $\lambda$ is very small for the NM calculation, the softening of phonon in the SAF phase may lead to a large increase in $\lambda$. In the SAF phase, strong anisotropy of the phonon softening in the Fe plane is found to arise from different spin orders in the $x$ and $y$ directions, indicating that the phonon softening is of spin-phonon coupling origin. For the SAF structure, the calculated variation trend of the electronic density of states and the phonon frequencies under pressure can explain a large negative pressure coefficient of $T_c$ in the LiFeAs compound.

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References in corpus (30)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• 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
• The superconductivity at 18 K in LiFeAs system
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and 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 at 27 K in tetragonal FeSe under high pressure
• 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
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Correlated electronic structure of LaOFeAs
• Electronic Structure and Doping in BaFe${}_2$As${}_2$ and LiFeAs: Density Functional Calculations
• Phase transitions in LaFeAsO: structural, magnetic, elastic, and transport properties, heat capacity and Mossbauer spectra
• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide
• Possible re-entrant superconductivity in EuFe2As2 under pressure
• Transport and anisotropy in single-crystalline SrFe${}_2$As${}_2$ and $A_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ ($A$ = Sr, Ba) superconductors
• SrFeAsF as a parent compound for iron pnictide superconductors
• Cobalt-substitution-induced Superconductivity in a New Compound with ZrCuSiAs-type Structure, SrFeAsF
• Electronic Structure of New LiFeAs High-Tc Superconductor
• Superconductivity in Fluorine-Arsenide Sr_{1-x}La_xFeAsF
• Pressure shift of the superconducting T_c of LiFeAs
• Lattice Dynamics of LaFeAsO_{1-x}F_{x} and PrFeAsO_{1-y} via Inelastic X-Ray Scattering and First-Principles Calculation
• Electronic and lattice dynamical properties of the iron-based superconductors LiFeAs and NaFeAs
• Striped antiferromagnetism and electronic structures of SrFeAsF and their implications
• Distorted magnetic orders and electronic structures of tetragonal FeSe from first-principles

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