Distinct signatures of particle-hole symmetry breaking in transport coefficients for generic multi-Weyl semimetals

We propose and study generic multi-Weyl semimetal (mWSM) lattice Hamiltonians that break particle-hole symmetry. These models fall into two categories: model I (model II) where the gap and tilt terms are coupled (decoupled) can host type-I and type-II Weyl nodes simultaneously (separately) in a hybrid phase (type-I and type-II phases, respectively). We concentrate on the question of how anisotropy and nonlinearity in the dispersions, gaps and tilt terms influence diffusive second-order transport quantities, namely, the circular photogalvanic effect (CPGE) and the Berry curvature dipole (BCD) as well as first-order Magnus Hall effect (MHE) in the ballistic limit. The signatures of topological charges are clearly imprinted in the quantized CPGE response for the hybrid mWSM phase in model I. Such a quantization is also found in the type-I WSM phase for model II, however, the frequency profiles of the CPGE in these two cases is distinctively different owing to their different band dispersion irrespective of the identical topological properties. The contributions from the vicinity of Weyl nodes and away from the WNs are clearly manifested in the BCD response, respectively, for models I and II. The Fermi surface properties for the activated momentum lead to a few hallmark features on the MHE for both models. Furthermore, we identify distinguishing signatures of the above responses for type-I, type-II, and hybrid phases to provide an experimentally viable probe to differentiate these WSMs phases.

Automated summary

This study focuses on the influence of anisotropy and nonlinearity in multi-Weyl semimetal lattice Hamiltonians on diffusive transport quantities. Clear signatures of specific topological features are identified, providing a potential means to differentiate between different phases of Weyl semimetals.