DFT+DMFT study of the magnetic susceptibility and the correlated electronic structure in transition-metal intercalated NbS$_2$

TL;DR

This study uses DFT+DMFT to explore how Co intercalation influences the magnetic and electronic properties of NbS$_2$, revealing how doping and Fermi surface features relate to magnetic ordering and experimental observations.

Contribution

It introduces a DMFT-based analysis of Co$_{1/3}$NbS$_2$, linking electronic structure, doping effects, and magnetic susceptibility with experimental data.

Findings

Hole doping tunes the Nb Fermi surface features.

Magnetic ordering wavevector matches neutron scattering results.

Results vary with different transition metal intercalations.

Abstract

The Co-intercalated NbS$_2$ (Co$_{1/3}$NbS$_2$) compound exhibits large anomalous Hall conductance, likely due to the non-coplanar magnetic ordering of Co spins. In this work, we study the relation between this novel magnetism and the correlated electronic structure of Co$_{1/3}$NbS$_2$ by adopting dynamical mean field theory (DMFT) to treat the correlation effect of Co $d$ orbitals. We find that the hole doping of Co$_{1/3}$NbS$_2$ can tune the size of the Nb hole pocket at the DMFT Fermi surface, producing features consistent with those observed in angle resolved photoemission spectra [Phys. Rev. B 105, L121102 (2022)]. We also compute the momentum-resolved spin susceptibility, and correlate it with the Fermi surface shape. We find that the magnetic ordering wavevector of Co$_{1/3}$NbS$_2$ obtained from the peak in spin susceptibility agrees with the one observed experimentally by neutron scattering; it is compatible with commensurate non-coplanar $3q$ spin structure. We also discuss how results change if some other than Co transition metal intercalations are used.