Fig. 3: Analysis of superconducting gaps and the bosonic mode in Ta-dopped CsV3Sb5 (CsV3-xTaxSb5, x = 0.10, 0.25 and 0.40).
From: Evidence of a distinct collective mode in Kagome superconductors
STM images obtained on the Sb surface of CsV2.90Ta0.10Sb5 (a), CsV2.75Ta0.25Sb5 (b), and CsV2.60Ta0.40Sb5 (c), respectively (Vs = –100 mV, It = 1 nA). The corresponding Fourier transform (inset) shows the disappearing of 2a0\(\times\)2a0 CDW with increasing of x. A series of dI/dV spectra obtained in different region on the Cs and Sb surface of CsV2.90Ta0.10Sb5 (d), CsV2.75Ta0.25Sb5 (e), and CsV2.60Ta0.40Sb5 (f) under the tunneling conditions Vs = –2 mV, Vmod = 0.05 mV, It = 1 nA, where the spatially-averaged spectra are highlighted in each stack plot by orange, green and sky-blue colors, respectively. Two-gap Dynes functions description of the spatially-averaged dI/dV spectra of CsV2.90Ta0.10Sb5 (g), CsV2.75Ta0.25Sb5 (h), and CsV2.60Ta0.40Sb5 (i), respectively. The experimental data (black circles) matches very well with the two-gap Dynes functions curves (colored solid lines). The features of bosonic modes manifest in their difference just outside the SC gaps marked by the shadowed region with cyan color. The two gap functions are shown as polar plots in the insets of (g–i). The red circles and blue circles in (a–c) represent the wave vectors of 2a0\({\times }\)2a0 CDW and Bragg peaks, respectively.
