Van Hove tuning of AV3Sb5 kagome metals under pressure and strain

TL;DR

This study uses first-principles calculations to explore how pressure and strain affect the structural and electronic properties of AV3Sb5 kagome metals, revealing a tunable van Hove point near the Fermi level that could influence superconductivity.

Contribution

It demonstrates that pressure and strain can effectively tune van Hove points in AV3Sb5, offering a new mechanism to control electronic correlations and superconductivity in kagome metals.

Findings

Charge ordering is suppressed under pressure.

Van Hove points can be shifted to the Fermi level with strain.

Potential for tuning superconductivity via strain and pressure.

Abstract

From first-principles calculations, we investigate the structural and electronic properties of the kagome metals AV3Sb5 (A = Cs, K, Rb) under isotropic and anisotropic pressure. Charge ordering patterns are found to be unanimously suppressed, while there is a significant rearrangement of p-type and m-type van Hove point energies with respect to the Fermi level. Already for moderate tensile strain along the V plane and compressive strain normal to the V layer, we find that a van Hove point can be shifted to the Fermi energy. Such a mechanism provides an invaluable tuning knob to alter the correlation profile in the kagome metal, and suggests itself for further experimental investigation. It might allow to reconcile possible multi-dome superconductivity in kagome metals not only from phonons, but also from the viewpoint of unconventional pairing.