Optical conductivities in triple fermions with different monopole charges

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Triple-component semimetals are a recently discovered class of topological materials.
• Their electronic properties, particularly optical conductivity, are not yet fully understood.
• The presence of flat bands in these materials suggests unique optical responses.

Purpose of the Study:

• To investigate the linear optical conductivities of triple-component semimetals.
• To understand the relationship between optical conductivity and the electronic band structure.
• To identify unique fingerprints for characterizing these materials.

Main Methods:

• Analysis of low-energy models with varying monopole charges.
• Deduction of the frequency dependence of interband conductivities.
• Investigation of lattice models to include optical anomalous Hall conductivity.
• Calculation of characteristic frequencies for kink structures.

Main Results:

• Diagonal conductivities exhibit strong anisotropy due to monopole charges.
• Interband conductivity shows a unique frequency dependence: linear for σxx and ω^2/ for σxy.
• Optical anomalous Hall conductivity was observed, with potential sign changes.
• Characteristic frequencies of kink structures were precisely calculated.

Conclusions:

• The study establishes a fundamental understanding of the linear optical response in topological triple-component semimetals.
• The unique optical conductivity signatures can be used to identify and differentiate these materials.
• This work provides a basis for future research into topological semimetals.