One-dimensionality signature in optical conductivity of heavy-fermion CeIr3B2

In low dimensions, the combined effects of interactions and quantum fluctuations can lead to dramatically new physics distinct from that existing in higher dimensions. Here, we investigate the electronic and optical properties of CeIr3B2, a quasione-dimensional (1D) Kondo lattice system, using ab initio calculations. The Ce atoms in the hexagonal crystal structure form 1D chains along the c axis, with extremely short Ce-Ce distances. The quasi-1D nature of the crystal structure is well reflected in its electronic structure. Extremely flat bands emerge within the ab plane of the Brillouin zone, yielding sharp optical transitions in the corresponding optical conductivity. Our calculations indicate that these prominent peaks in the optical conductivity provide a clear signature of quasi-1D heavy fermion systems.