Quasi-One-Dimensional Fermi Surface Nesting and Hidden Nesting Enable Multiple Kohn Anomalies in α-Uranium

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Physics

Background:

• Fermi surface topology dictates a metal's electronic response, including charge density wave (CDW) formation.
• Fermi surface nesting (FSN) can induce CDWs and anomalous lattice dynamics, known as Kohn anomalies.
• Materials exhibiting multiple Kohn anomalies are uncommon.

Purpose of the Study:

• Investigate the origins of multiple Kohn anomalies in α-uranium.
• Explore the role of Fermi surface nesting and hidden nesting in these phenomena.
• Understand the implications for electronic and lattice properties.

Main Methods:

• First-principles simulations of electronic susceptibility (χ₀) and lattice dynamical susceptibility (χL'').
• Analysis of existing scattering measurements.
• Theoretical investigation of Fermi surface nesting and hidden nesting effects.

Main Results:

• α-uranium exhibits multiple Kohn anomalies.
• The combined effects of FSN and hidden nesting are responsible for these anomalies.
• Hidden nesting, involving electronic states above and below the Fermi surface, contributes to a ridgelike feature in χ₀, enhancing interatomic force modulation.

Conclusions:

• Hidden nesting is crucial for controlling electronic and lattice susceptibilities.
• This understanding can guide the engineering of advanced materials, such as topological Weyl semimetals and superconductors.
• The study highlights a rare instance of multiple Kohn anomalies and their underlying mechanisms.