Tunneling STM/STS and break-junction spectroscopy of the Pb-doped Bi2223 superconductor. Issue 1 (July 2021)

• Record Type: Journal Article
• Authors: Sugimoto, Akira; Ohtsubo, Hironori; Matsumoto, Kaito; Ishimitsu, Satoru; Iwano, Masatoshi; Ekino, Toshikazu; Gabovich, A M
• Is Part Of: Journal of physics. Volume 1975:Issue 1(2021)
• Publication Date: 2021-07
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1975/1/012005
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The combined scanning tunneling microscopy/spectroscopy (STM/STS) and the break-junction tunneling spectroscopy (BJTS) measurements of the three-layered Pb x Bi2- x Sr2 Ca2 Cu3 O10+y cuprate superconductors were carried out. The averaged dI/dV spectrum obtained by the STS shows the gap Δ STS ≈ 45 meV, while that of BJTS shows Δ BJ ≈ 35 meV. In case of the BJTS measurements, we also referred the zero bias (ZB) peak as being due to the maximum Josephson current IJc . The product of IJc and normal resistance RN ( IJc RN ) was obtained IJc RN ≈ 3.5 mV at T = 11 K, which is one order lower than that of the BCS-based Ambegaokar-Baratoff theory with Δ BJ =35 meV taken into account. With increasing the temperature, the IJc RN was reduced and vanished just below the Tc (≈ 106 K), indicating the bulk superconductivity. Simultaneously, from the temperature dependence of the gap features from 80 K to 120 K, the gap Δ was shown to persist across the Tc, indicating that the IJc RN product is a significant parameter for understanding the cuprate superconductivity.