Coupling of structure to magnetic and superconducting orders in quasi-one-dimensional ${\text{K}}_2{\text{Cr}}_3{\text{As}}_3$

Abstract

Quasi-one-dimensional $A_2{\text{Cr}}_3{\text{As}}_3$ (with $A=\text{K, Cs, Rb}$) is an intriguing new family of superconductors which exhibit many similar features to the cuprate and iron-based unconventional superconductor families. Yet in contrast to these systems, no charge or magnetic ordering has been observed which could provide the electronic correlations presumed necessary for an unconventional superconducting pairing mechanism - an absence which defies predictions of first principles models. We report the results of neutron scattering experiments on polycrystalline ${\text{K}}_2{\text{Cr}}_3{\text{As}}_3$ $(T_c\sim 7\text{K})$ which probed the low temperature dynamics near $T_c$ . Neutron diffraction data evidence a strong response of the nuclear lattice to the onset of superconductivity while inelastic scattering reveals a highly dispersive column of intensity at the commensurate wavevector $q=(00\frac{1}{2})$ which loses intensity beneath $T_c$ - indicative of short-range magnetic fluctuations. Using linear spin-wave theory we model the observed scattering and suggest a possible structure to the short-range magnetic order. These observations suggest that ${\text{K}}_2{\text{Cr}}_3{\text{As}}_3$ is in close proximity to a magnetic instability and that the incipient magnetic order both couples strongly to the lattice and competes with superconductivity - in direct analogy with the iron-based superconductors.

References in corpus (12)

• Superconductivity and Crystal Structures of (Ba1-xKx)Fe2As2 (x = 0 - 1)
• Superconductivity in quasi-one-dimensional K${}_2$Cr${}_3$As${}_3$ with significant electron correlations
• Unconventional superconductivity in quasi-one-dimensional Rb${}_2$Cr${}_3$As${}_3$
• Superconductivity in quasi-one-dimensional Cs2Cr3As3 with large interchain distance
• Spin fluctuations in LiFeAs observed by neutron scattering
• Strong $(\pi ,0)$ spin fluctuations in $\beta$-FeSe observed by neutron spectroscopy
• Magnetism in Quasi-One-Dimensional A${}_2$Cr${}_3$As${}_3$ (A=K,Rb) superconductors
• Multiband one-dimensional electronic structure and spectroscopic signature of Tomonoga-Luttinger liquid behavior in K${}_2$Cr${}_3$As${}_3$
• Cluster spin-glass ground state in quasi-one-dimensional KCr${}_3$As${}_3$
• Coincident structural and magnetic order in BaFe${}_2$(As${}_{1-x}$)P${}_x$)${}_2$ revealed by high-resolution neutron diffraction
• Local orthorhombicity in the magnetic $C_4$ phase of the hole-doped iron-arsenide superconductor Sr${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$
• Competing superconducting and magnetic order parameters and field-induced magnetism in electron doped Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$

Cited by in corpus (2)

• Structural Instability and Magnetism of Superconducting KCr${}_3$As${}_3$
• K2Mo3As3 is a Multi-Gap Electron-Phonon Superconductor