Landau levels and magneto-optical responses in Weyl semimetal quantum wells in a non-uniform magnetic field

We study the Landau level (LL) structure and magneto-optical responses in the Weyl semimetal (WSM) quantum well in the presence of a non-uniform magnetic field (NUMF). The number of LLs in the NUMF is found to be finite, and the LL structure of the system is significantly affected by the inhomogeneity of the magnetic field. The added electric field significantly affects the separation of the two Weyl nodes in momentum space. We investigate the role of the inhomogeneity of the magnetic field, temperature, electron density, and electric field, as well as the doping level on the optical response properties. Both longitudinal and Hall susceptibilities in the (x, y) plane and the longitudinal susceptibility in the z direction display a series of peaks whose height and spacing decrease with the increase of the LL index. At T not equal 0, thermal excitation triggers new transitions, which are forbidden by the Pauli blocked at T = 0. The optical response spectra are different when the chemical potential lies in different energy regions, which are strongly dependent on the inhomogeneity of the magnetic field, electron density, and electric field. In this paper, we provide a possible way to control the optical response spectrum in WSM materials by changing these parameters.