Kondo resonance in a magnetically ordered compound ${\text{Ce}}_2{\text{RhSi}}_3$: Photoemission spectroscopy and ab initio band structure calculations

We study the electronic structure of an antiferromagnetic metal, ${\text{Ce}}_2{\text{RhSi}}_3$ $\left(T_N<7\text{K}\right)$, using high-resolution photoemission spectroscopy and ab initio band structure calculations. The valence-band spectra at higher binding energies are well described within the local-density approximations. The high-resolution spectra near Fermi level reveals the emergence of the Kondo resonance features with the decrease in temperature, which are distinctly different from the features appearing due to magnetic $\text{Ce}4f$ contributions. These results provide a direct evidence that the Kondo compensation effect of the local moments persists in this magnetically ordered compound, thereby, supporting the validity of the ideas based on spin-density-wave state as quantum criticality is approached.

Figure 1

(Color online) Calculated (a) $\text{Ce}5d$ PDOS, (b) $\text{Ce}4f$ PDOS, (c) $\text{Rh}4d$ PDOS, and (d) $\text{Si}3p$ PDOS. ($\text{Ce}4f$ $\text{PDOS}\times 75+10$) is shown by thick line in (b) for clarity in the higher binding energy region.

Figure 2

(Color online) (a) Valence-band spectra collected at 10 K using $\text{He}\text{I}$, $\text{He}\text{II}$, and $\text{Al}K\alpha$ excitation energies. The calculated $\text{Al}K\alpha$ spectrum from the ab initio results are also shown along with the relative contributions from $\text{Rh}4d$, $\text{Si}3p$, and $\text{Ce}4f$ electronic states. The background subtraction procedure for two representative cases (b) $\text{Al}K\alpha$ and (c) $\text{He}\text{II}$ spectra are also shown. The open symbols are the raw data, line is the background, and solid symbols are the background subtracted data.

Figure 3

(Color online) (a) $\text{He}\text{II}$ (symbols) and $\text{He}\text{I}$ (line) spectra at 10 K. The subtracted ($\text{He}\text{II}$-$\text{He}\text{I}$) spectra at different temperatures are shown in the bottom panel. (b) Schematic description of possible final states corresponding to the $\text{Ce}4f$ photoemission having $|f^1⟩$ initial-state configuration.

Figure 4

(Color online) Core-level spectra at 300 K (symbols) and 10 K (dashed line). The 10 K spectra is broadened by a Gaussian and shown by solid line. The solid and dashed lines in (f) for $\text{Ce}3d_{5/2}$ feature are identical.