研究目的
To investigate the optical and energy loss spectra of transition metal monopnictides TaAs, TaP, NbAs, and NbP, which are topological semimetals with Weyl fermions, across a wide spectral energy range using density functional theory.
研究成果
The study provides a comprehensive analysis of the optical and energy loss spectra of transition metal monopnictides, highlighting the importance of cation f and p semi-core states in high-energy transitions. The findings suggest that these materials have potential applications in opto-electronic devices due to their unique optical properties.
研究不足
The study does not account for the influence of polar optical phonons and intraband electronic transitions in the low-energy range, which are important for experimental comparisons. Additionally, the Weyl fermion picture's special behavior in the infrared limit of the reflectivity is not fully explored.
1：Experimental Design and Method Selection:
The study employs density functional theory (DFT) within the generalized gradient approximation (GGA) scheme, using the QUANTUM ESPRESSO (QE) Package for structural, electronic, and optical properties calculations. The Yambo code is used for optical and energy loss spectra computations, taking into account the non-locality of the pseudopotentials.
2：Sample Selection and Data Sources:
The study focuses on transition metal monopnictides TaAs, TaP, NbAs, and NbP, with electronic configurations specified for each element to generate fully relativistic, norm-conserving pseudopotentials.
3：List of Experimental Equipment and Materials:
The computational setup includes a suitable energy cut-off of 100 Ry and a uniform grid of k points for sampling the Brillouin zone (BZ).
4：Experimental Procedures and Operational Workflow:
The atomic geometries are optimized starting from reference Wyckoff positions for the I41md group. Optical properties are computed within the single-particle approximation in the transverse gauge.
5：Data Analysis Methods:
The imaginary part of the dielectric function is calculated, and the real part is obtained via the Kramers-Kronig relation. Energy loss spectra are calculated for vanishing momentum transfer.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
