Friedel Oscillations of Vortex Bound States under Extreme Quantum Limit in KCa2Fe4As4F2

被引：29

作者：

Chen, Xiaoyu ^{[1
,2
]}

Duan, Wen ^{[1
,2
]}

Fan, Xinwei ^{[1
,2
]}

Hong, Wenshan ^{[3
,4
]}

Chen, Kailun ^{[1
,2
]}

Yang, Huan ^{[1
,2
]}

Li, Shiliang ^{[3
,4
,5
]}

Luo, Huiqian ^{[3
,5
]}

Wen, Hai-Hu ^{[1
,2
]}

机构：

[1] Nanjing Univ, Collaborat Innovat Ctr Adv Microstruct, Natl Lab Solid State Microstruct, Nanjing 210093, Peoples R China

[2] Nanjing Univ, Collaborat Innovat Ctr Adv Microstruct, Dept Phys, Nanjing 210093, Peoples R China

[3] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China

[4] Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100190, Peoples R China

[5] Songshan Lake Mat Lab, Dongguan 523808, Guangdong, Peoples R China

来源：

PHYSICAL REVIEW LETTERS | 2021年 / 126卷 / 25期

基金：

中国国家自然科学基金; 国家重点研发计划; 北京市自然科学基金;

关键词：

TUNNELING SPECTROSCOPY; CORE STRUCTURE; SUPERCONDUCTORS; DENSITY; LINE;

D O I：

10.1103/PhysRevLett.126.257002

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report the observation of discrete bound states with the energy levels deviating from the widely believed ratio of 1 :3 :5 in the vortices of an iron-based superconductor KCa2Fe4As4F2 through scanning tunneling microscopy (STM). Meanwhile Friedel oscillations of vortex bound states are also observed for the first time in related vortices. By doing self-consistent calculations of Bogoliubov-de Gennes equations, we find that at extreme quantum limit, the superconducting order parameter exhibits a Friedel-like oscillation, which modifies the energy levels of the vortex bound states and explains why it deviates from the ratio of 1 :3 :5. The observed Friedel oscillations of the bound states can also be roughly interpreted by the theoretical calculations, however some features at high energies could not be explained. We attribute this discrepancy to the high energy bound states with the influence of nearby impurities. Our combined STM measurement and the self-consistent calculations illustrate a generalized feature of vortex bound states in type-II superconductors.

引用

页数：6

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[31] Friedel oscillation in charge profile and position dependent screening around a superconducting vortex core [J].