Abstract
We report on soft c-axis point-contact Andreev reflection(PCAR)spectroscopy combining with resistivity measurements on BaFe2(As0.7P0.3)2,to elucidate the superconducting gap structure in the vicinity of the quan-tum 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 BaFe2(As0.7P0.3)2.Detailed analysis within a sophisticated theoretical model reveals an anisotropic gap with deep gap minima.The PCARs also feature ad-ditional structures related to the electron-bosonic coupling mode.Using the extracted superconducting energy gap value,a characteristic bosonic energy Ωb and its temperature dependence are obtained,comparable with the spin-resonance energy observed in neutron scattering experiment.These results indicate a magnetism-driven quantum critical point in the BaFe2(As1-xPx)2 system.
基金项目
国家自然科学基金(11774303)
国家自然科学基金(11574373)
国家重点研发计划(2022YFA1403402)
国家重点研发计划(2021YFA1400401)
国家重点研发计划(2020YFA0406003)
中国科学院项目(XDB33000000)
中国科学院项目(GJTD-2020-01)
Joint Fund of Yunnan Provincial Science and Technology Department(2019FY003008)
万方数据