Elastic Gauge Fields in Weyl Semimetals.

Area of Science:

• Condensed matter physics
• Materials science
• Quantum mechanics

Background:

• Elastic deformations in materials can influence electronic properties.
• Weyl semimetals exhibit unique electronic band structures with Weyl nodes.
• Graphene demonstrates coupling between elasticity and electronic degrees of freedom.

Purpose of the Study:

• To investigate the coupling of elastic deformations to electronic degrees of freedom in Weyl semimetals.
• To derive the form of elastic gauge fields in a tight-binding model of Weyl semimetals.
• To explore new response functions arising from these elastic gauge fields.

Main Methods:

• Utilizing a tight-binding model for Weyl semimetals.
• Deriving the mathematical form of pseudogauge fields from elastic deformations.
• Calculating response functions, specifically phonon Hall viscosity.

Main Results:

• Elastic deformations couple to electronic degrees of freedom as pseudogauge fields in Weyl semimetals.
• The derived electron-phonon coupling is chiral, manifesting as axial gauge fields in 3D.
• A nonzero phonon Hall viscosity was derived for the neutral system at zero temperature.

Conclusions:

• The study establishes a connection between mechanical strain and electronic behavior in Weyl semimetals via axial gauge fields.
• The findings provide a new avenue for testing the chiral anomaly in condensed matter systems.
• The derived phonon Hall viscosity represents a novel response function linked to elastic gauge fields.