Electronic effect of doped oxygen atoms in Bi2201 superconductors determined by scanning tunneling microscopy  

作　　者：Ying Fei KunLiang Bu WenHao Zhang Yuan Zheng Xuan Sun Ying Ding XingJiang Zhou Yi Yin 

机构地区：[1]Department of Physics,Zhejiang University,Hangzhou 310027,China [2]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [3]Collaborative Innovation Center of Quantum Matter,Beijing 100871,China [4]Collaborative Innovation Center of Advanced Microstructures,Nanjing 210093,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2018年第12期30-36,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant Nos.2015CB921004,and 2014CB921203);the National Natural Science Foundation of China(Grant Nos.NSFC-11374260,and NSFC-11334010);the Fundamental Research Funds for the Central Universities in China(Grant No.2016XZZX002-01);the National Key Research and Development Program of China(Grant No.2016YFA0300300);and the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB07020300)

摘　　要：Oxygen dopants are essential for tuning the electronic properties of the cuprate superconductors Bi_2Sr_2Ca_(n-1)Cu_nO_(2n+4+δ).Here,we study an optimally doped Bi_2Sr_(2-x)La_xCuO_(6+δ)and an overdoped Bi_(2-y)Pb_ySr_2CuO_(6+δ)by scanning tunneling microscopy and spectroscopy(STM/STS).Based on the characteristic features of local STS,three forms of oxygen dopants are identified:interstitial oxygen atoms on the SrO layers,oxygen vacancies on the SrO layers,and interstitial oxygen atoms on the BiO layers.In both samples,the first form dominates the number of oxygen dopants.From the extracted spatial distribution of the oxygen dopants,we calculate the dopant concentrations and estimate the average hole carrier density.The magnitudes of the electronic pseudogap state in both samples are inhomogeneously distributed in space.The statistical analysis on the spatial distributions of the oxygen dopants and the pseudogap magnitude demonstrates that the doped oxygen atoms on the SrO layers tend to suppress the nearby pseudogap magnitude.Oxygen dopants are essential for tuning the electronic properties of the cuprate superconductors Bi_2Sr_2Ca_(n-1)Cu_nO_(2n+4+δ).Here,we study an optimally doped Bi_2Sr_(2-x)La_xCuO_(6+δ)and an overdoped Bi_(2-y)Pb_ySr_2CuO_(6+δ)by scanning tunneling microscopy and spectroscopy(STM/STS).Based on the characteristic features of local STS,three forms of oxygen dopants are identified:interstitial oxygen atoms on the SrO layers,oxygen vacancies on the SrO layers,and interstitial oxygen atoms on the BiO layers.In both samples,the first form dominates the number of oxygen dopants.From the extracted spatial distribution of the oxygen dopants,we calculate the dopant concentrations and estimate the average hole carrier density.The magnitudes of the electronic pseudogap state in both samples are inhomogeneously distributed in space.The statistical analysis on the spatial distributions of the oxygen dopants and the pseudogap magnitude demonstrates that the doped oxygen atoms on the SrO layers tend to suppress the nearby pseudogap magnitude.

关 键 词：CUPRATE SUPERCONDUCTOR scanning TUNNELING spectroscopy DOPING hole concentration PSEUDOGAP 

分 类 号：N[自然科学总论]