Electromagnetic Response of Weyl Semimetals

Understand

It has been suggested recently, based on subtle field-theoretical considerations, that the electromagnetic response of Weyl semimetals and the closely related Weyl insulators can be characterized by an axion term E.B with space and time dependent axion angle.

• Here we construct a minimal lattice model of the Weyl medium and study its electromagnetic response by a combination of analytical and numerical techniques.
• We confirm the existence of the anomalous Hall effect expected on the basis of the field theory treatment.
• We find, contrary to the latter, that chiral magnetic effect (that is, ground-state charge current induced by the applied magnetic field) is absent in both the semimetal and the insulator phase.