Zou Changwei, Hao Zhenqi, Li Haiwei, Li Xintong, Ye Shusen, Yu Li, Lin Chengtian, Wang Yayu
State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Phys Rev Lett. 2020 Jan 31;124(4):047003. doi: 10.1103/PhysRevLett.124.047003.
We investigate the spatial and doping evolutions of the superconducting properties of trilayer cuprate Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+δ} by using scanning tunneling microscopy and spectroscopy. Both the superconducting coherence peak and gap size exhibit periodic variations with structural supermodulation, but the effect is much more pronounced in the underdoped regime than at optimal doping. Moreover, a new type of tunneling spectrum characterized by two superconducting gaps emerges with increasing doping, and the two-gap features also correlate with the supermodulation. We propose that the interaction between the inequivalent outer and inner CuO_{2} planes is responsible for these novel features that are unique to trilayer cuprates.
我们利用扫描隧道显微镜和光谱学研究了三层铜酸盐Bi₂Sr₂Ca₂Cu₃O₁₀₊δ超导特性的空间和掺杂演变。超导相干峰和能隙大小都随结构超调制呈现周期性变化,但这种效应在欠掺杂区域比在最佳掺杂时更为明显。此外,随着掺杂增加,出现了一种以两个超导能隙为特征的新型隧道谱,且双能隙特征也与超调制相关。我们提出,不等价的外层和内层CuO₂平面之间的相互作用导致了这些三层铜酸盐特有的新颖特征。