Electronic and dynamical properties of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>CeRh</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>As</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>: Role of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Rh</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>As</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> layers and expected orbital order
Andrzej Ptok, Konrad Jerzy Kapcia, Paweł T. Jochym, Jan Łażewski, Andrzej M. Oleś, Przemysław Piekarz
Abstract
The recently discovered heavy fermion ${\mathrm{CeRh}}_{2}{\mathrm{As}}_{2}$ compound crystallizes in nonsymmorphic $P4/nmm$ symmetry, which enables the occurrence of topological protection. Experimental results show that this material exhibits unusual behavior, which is manifested by the appearance of two superconducting phases. In this Letter, we uncover and discuss the role of ${\mathrm{Rh}}_{2}{\mathrm{As}}_{2}$ layers and their impact on the electronic and dynamical properties of the system. The location of Ce atoms between two nonequivalent layers allows for the realization of orbital order. We point out that the electronic band structure around the Fermi level is associated mostly with Ce $4f$ and Rh $4d$ orbitals and suggest the occurrence of the Lifshitz transition induced by an external magnetic field. We discuss also the role played by the $f\ensuremath{-}d$ orbital hybridization in the electronic band structure.