Temperature-dependent electronic structure and topological property of the Kondo semimetal CeFe2Al10

Abstract

We have investigated the electronic structure and the topological property of a Ce Kondo system, ${\mathrm{CeFe}}_{2}{\mathrm{Al}}_{10}$, employing the first-principles density functional theory (DFT) and dynamical mean-field theory (DMFT) band calculations. Based on the DMFT band calculation, we have found that, upon cooling, Ce $4f$ electrons in ${\mathrm{CeFe}}_{2}{\mathrm{Al}}_{10}$ become coherent at $T\ensuremath{\approx}150$ K, so as to form coherent bands revealing the hybridization pseudogap near the Fermi level (${E}_{\text{F}}$). We have checked that the band structure near ${E}_{\text{F}}$ and the Fermi surface from the DMFT at low $T$ are almost identical with those from the renormalized DFT. We have explored the topological nature based on the DFT band structure and found that ${\mathrm{CeFe}}_{2}{\mathrm{Al}}_{10}$ has a topological Kondo insulating nature with ${Z}_{4}=1$. Therefore, our finding reveals that ${\mathrm{CeFe}}_{2}{\mathrm{Al}}_{10}$ would display $T$-dependent topological phase transition from a topological Kondo insulating phase at low $T$ to a trivial semimetallic phase at high $T$. The analysis of $T$-dependent local magnetic susceptibility obtained from the DMFT calculation confirms the Kondo coherence mechanism upon cooling in ${\mathrm{CeFe}}_{2}{\mathrm{Al}}_{10}$.