Temperature dependence of the Kondo resonance peak in photoemission spectra of YbCdCu4

Temperature Dependence of the Kondo Resonance Peak in Photoemission Spectra of Rare-Earth Compound YbMgCu4

“…Figure 1(a) shows the valence-band spectra of YbMgCu 4 measured at T = 8 K. The spin-orbit splitting of the Yb 2+ 4 f 7/2 and Yb 2+ 4 f 5/2 states are observed at |ω| ∼ 0.07 eV and 1.36 eV, respectively. These assignments are consistent with the results obtained by the photoemission spectroscopy with vacuum ultraviolet and hard X-ray photons [10][11][12][13]. The full width at half-maximum, 0.107 eV, of the 4 f 7/2 peak is much narrower than the results reported in previous photoemission studies [8,9].…”

“…The intensity of the Kondo peak indicates the strength of the c-f hybridization [14,15]. Recent photoemission studies on YbCdCu 4 have revealed an enhancement of the peak intensity at low temperatures [13]. For the case of YbMgCu 4 , where T K is three to four times larger than that of YbCdCu 4 , the intense peak remains in a wide temperature range 8 ≤ T ≤ 187 K, demonstrating the robustness of the Kondo singlet state [16].…”