Anisotropic s-Wave Gap in the Vicinity of a Quantum Critical Point in Superconducting BaFe_(2)(As_(1-x)P_(x))_(2) Single Crystals:A Study of Point-Contact Spectroscopy

作     者：詹红星 林玉尺 赵宇清 左海艳 王兴玉 马肖燕 李春红 罗会仟 陈根富 李世亮 任聪 Hong-Xing Zhan;Yu-Chi Lin;Yu-Qing Zhao;Hai-Yan Zuo;Xing-Yu Wang;Xiao-Yan Ma;Chun-Hong Li;Hui-Qian Luo;Gen-Fu Chen;Shi-Liang Li;Cong Ren

作者机构：School of Physics and AstronomyYunnan UniversityKunming 650500China Beijing National Laboratory for Condensed Matter Physicsand Institute of PhysicsChinese Academy of SciencesBeijing 100190China Yunnan Key Laboratory for Electromagnetic Materials and DevicesYunnan UniversityKunming 650500China 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2024年第41卷第4期

页      面：118-123页

核心收录：

学科分类：080705[工学-制冷及低温工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0807[工学-动力工程及工程热物理] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11774303 and 11574373) the National Key Research and Development Program of China(Grant Nos.2022YFA1403402,2021YFA1400401,and 2020YFA0406003) the Chinese Academy of Sciences(Grant Nos.XDB33000000 and GJTD-2020-01) financial support from the Joint Fund of Yunnan Provincial Science and Technology Department(Grant No.2019FY003008) 

主　　题：quantum critical resistivity 

摘      要：We report on soft c-axis point-contact Andreev reflection(PCAR)spectroscopy combining with resistivity measurements on BaFe_(2)(As_(0.7)P_(0.3))_(2),to elucidate the superconducting gap structure in the vicinity of the quantum critical point.A double peak at the gap edge plus a dip feature at zero-bias has been observed on the PCAR spectra,indicative of the presence of a nodeless gap in BaFe_(2)(As_(0.7)P_(0.3))_(2).Detailed analysis within a sophisticated theoretical model reveals an anisotropic gap with deep gap *** PCARs also feature additional structures related to the electron-bosonic coupling *** the extracted superconducting energy gap value,a characteristic bosonic energy Ω_(b) and its temperature dependence are obtained,comparable with the spin-resonance energy observed in neutron scattering *** results indicate a magnetism-driven quantum critical point in the BaFe_(2)(As_(1-x)P_(x))_(2) system.