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)

Normalized tunneling spectra of underdoped Ba_{1− x}K_xFe₂As₂ single crystals with (a) T _c = 22 K and (b) T _c = 16 K. All the spectra were taken at 2.2 K. The grey vertical lines indicate the features of superconducting gaps, while the black arrows indicate the hump-dip feature.