Merging of momentum-space monopoles by controlling magnetic field: From cubic-Dirac to triple-Weyl fermion systems

Abstract

We analyze a generalized Dirac system, where the dispersion along the $k_x$ and $k_y$ axes is $N$-th power and linear along the $k_z$ axis. When we apply magnetic field, there emerge $N$ monopole-antimonopole pairs beyond a certain critical field in general. As the direction of the magnetic field is rotated toward the $z$ axis, monopoles move to the north pole while antimonopoles move to the south pole. When the magnetic field becomes parallel to the $z$ axis, they merge into one monopole or one antimonopole whose monopole charge is $\pm N$. The resultant system is a multiple-Weyl semimetal. Characteristic properties of such a system are that the anomalous Hall effect and the chiral anomaly are enhanced by $N$ times and that $N$ Fermi arcs appear. These phenomena will be observed experimentally in the cubic-Dirac and triple-Weyl fermion systems ($N=3$).

5 pages, 3 figures

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Cited by in corpus (3)

• Topological quantum critical point in a triple-Weyl semimetal: non-Fermi-liquid behaviors and instabilities
• Cubic Dirac and quadruple Weyl points in screw-symmetric materials
• Exact solutions of Kondo problems in higher-order fermions