Observation of mode-like features in tunneling spectra of iron-based superconductors<xref ref-type="fn" rid="cpb151073fn1">*</xref>

Observation of mode-like features in tunneling spectra of iron-based superconductors*

Gong Jing^a), Hou Xing-Yuan^a), Zhu Jun^a), Jie Yun-Yin^a), Gu Ya-Dong^a),^b), Shen Bing^a), Ren Cong^a), Li Chun-Hong^a), Shan Lei†^a),^c)

(a) Normalized tunneling spectra of nearly optimally doped Ba_{1− x}K _x Fe₂As₂ single crystals ( x = 0.4) measured at 3.5 K. The grey vertical lines indicate the features of superconducting gaps, while the black arrows indicate the hump-dip feature mentioned in the paper. (b) Comparison between two spectra measured at low temperature and above T _c. (c) Derivative of the low-temperature spectrum shown in panel (b). The grey vertical lines indicate the features of superconducting gaps, while the black arrows indicate the hump-dip feature. The data in panels (b) and (c) are the same as what we have reported previously.^{[ 28 ]}