Magneto-optical Kerr effect and signature of the chiral anomaly in a Weyl semimetal in magnetic field

Kerr effect in tilted nodal loop semimetals

“…[17,18] for different parameter regimes and it was found that Weyl semimetals show signatures of large Kerr rotations as well. Furthermore, a very recent paper by Parent et al shows how the Kerr effect in Weyl semimetals is affected by magnetic fields and demonstrates how a valley polarization and the chiral anomaly can be observed in the Kerr angle [19]. Some aspects of the optical responses of nodal loop semimetals have already been reported in Refs.…”

Magneto-optical Kerr effect in Weyl semimetals with broken inversion and time-reversal symmetries

“…The optical selections rules imposed by the matrix elements are such that only the dipolar transitions |n| = |n| ± 1 (here n = 0, ±1, ±2, ...) are permitted in χ χ,(α,β) with α , β = x, y while only the transitions −n → n are permitted in χ χ,(z,z) . (A tilt of a Weyl cone allows for a much richer interband spectrum 15,22 ). We limit our study to the ultra-quantum regime where the Fermi level lies in the chiral level.…”

“…They also found a large Kerr effect caused by the axion term b in a bulk WSM. In a previous paper by one of us 15 , it was shown that the MOKE in a Weyl semimetal with time-reversal symmetry (i.e., b = 0) and tilted Weyl cones in a strong magnetic field is modified in comparison with its behavior in a normal metal. It was also shown that a valley polarization 16 can be detected in the MOKE signal which also bears a signature of the chiral anomaly in the form of a large peak at the plasmon frequency in the Kerr angle in the Voigt configuration.…”

Quantum magnetic oscillations in Weyl semimetals with tilted nodes

“…E n=0 (k) = −χℏv F k, where χ is the chirality index. The presence of this chiral level affects many properties of Weyl semimetals such as the optical absorption spectrum which is different from that of Schrödinger or Dirac fermions 7,8 or the Faraday and Kerr effects [9][10][11] .…”