Electronic structure of quasi-one-dimensional superconductor K2Cr3As3 from first-principles calculations.

Hao Jiang,Guanghan Cao,Chao Cao

doi:10.1038/srep16054

Abstract

The electronic structure of quasi-one-dimensional superconductor K2Cr3As3 is studied through systematic first-principles calculations. The ground state of K2Cr3As3 is paramagnetic. Close to the Fermi level, the , dxy, and orbitals dominate the electronic states, and three bands cross EF to form one 3D Fermi surface sheet and two quasi-1D sheets. The electronic DOS at EF is less than 1/3 of the experimental value, indicating a large electron renormalization factor around EF. Despite of the relatively small atomic numbers, the antisymmetric spin-orbit coupling splitting is sizable (≈60 meV) on the 3D Fermi surface sheet as well as on one of the quasi-1D sheets. Finally, the imaginary part of bare electron susceptibility shows large peaks at Γ, suggesting the presence of large ferromagnetic spin fluctuation in the compound.

Highlights

The electronic structure of quasi-one-dimensional superconductor K2Cr3As3 is studied through systematic first-principles calculations
It is quite essential to study the electronic structure of this compound, in particular its ground state, the spin-orbit coupling effect, as well as the possible spin fluctuations
Since the Cr sub-lattice is magnetically strongly frustruated, we considered several different possible magnetic states in our current study: the ferromagnetic state (FM), the inter-layer antiferromagnetic state (IAF)(Fig. 1c), the noncollinear antiferromagnetic state (NCL)(Fig. 1d), the noncollinear in-out state (IOP) (Fig. 1e), the noncollinear chiral-like state (CLK) (Fig. 1f), and the nonmagnetic state (NM)

Summary

Introduction

The electronic structure of quasi-one-dimensional superconductor K2Cr3As3 is studied through systematic first-principles calculations. The upper critical field of Tl2Mo6Se6 is 5.9 T and 0.47 T parallel and perpendicular to the quasi-1D direction[15], respectively Such unusually high Hc2 is beyond the explanation of multiband effect and spin-orbit scattering, and usually implies possible spin triplet www.nature.com/scientificreports/. It is quite essential to study the electronic structure of this compound, in particular its ground state, the spin-orbit coupling effect, as well as the possible spin fluctuations. The Fermi surfaces of K2Cr3As3 consist of one 3D sheet and two quasi-1D sheets, and the Cr-3d orbitals, in particular the dz[2], dxy, and dx2−y2 orbitals dominate the electronic states around EF

Methods

Results

Conclusion