Electronic properties of Kagome metal YbV$_3$Sb$_4$: A First-Principles Study

TL;DR

This study uses first-principles calculations to analyze the electronic structure, Fermi surface, and topological properties of YbV$_3$Sb$_4$, revealing its potential for exploring quantum phenomena in Kagome metals.

Contribution

It provides a comprehensive DFT analysis of YbV$_3$Sb$_4$, highlighting the effects of SOC and U+SOC on electronic states, Fermi surface topology, and topological invariants, which was not previously reported.

Findings

YbV$_3$Sb$_4$ is a strong topological metal with a $Z_2$ invariant of 1.

SOC and U+SOC significantly alter Yb-4f states and Fermi surface features.

Fermi surface comprises quasi-2D cylindrical sheets with small pockets, with modifications under U+SOC.

Abstract

We have investigated the vanadium-based Kagome metal YbV$_3$Sb$_4$ using density functional theory (DFT) combined with the Wannier function analysis. We explore the electronic properties, de Haas-van Alphen (dHvA) effect and Fermi surface. The inclusion of spin-orbit coupling SOC induces the splitting of Yb-4f states, while its impact on the V-3d states is moderate. Furthermore, we have incorporated SOC+U, where U being the Hubbard parameter, which drastically changes the Yb-4f states creating additional splitting leading to three distinct peaks in the density of states (DOS). The V-3d atoms with the Kagome lattice contribute maximum to the transport properties, exhibits flat bands near the EF while being protected under SOC and U+SOC. Herein, we report the vulnerability of the Yb-4f states under SOC and U+SOC. Furthurmore, The Fermi surface is found to comprise of quasi-2D cylindrical sheets centered at the Gamma-point, along with smaller pockets near the Brillouin zone boundaries, which under combined U+SOC, a small spherical pocket emerges and the cylindrical sheet exhibits slight deformations. The dHvA frequencies reach as high as 70 kilotesla, which increase with tilt angle, exhibiting a nearly parabolic trend as expected for cylindrical orbits, while a low-frequency branch remains below 1 kT. Only the U+SOC case shows noticeable modification in both the Fermi surface and the dHvA oscillation. Crucially, the $Z_2$ invariant calculation identifies YbV$_3$Sb$_4$ as a strong topological metal ($r_0 = 1$). These findings not only advance our understanding of the underlying quantum phenomena in rare-earth Kagome systems, but also establish YbV$_3$Sb$_4$ as a compelling and promising platform for exploring intertwined topology and electron correlations in kagome lattices, thereby offering valuable insights for engineering quantum phases in layered materials.