Title: Observation of magnetic adatom-induced Majorana vortex and its hybridization with field-induced Majorana vortex in an iron-based superconductor

Abstract

Braiding Majorana zero modes is essential for fault-tolerant topological quantum computing. Iron-based superconductors with nontrivial band topology have recently emerged as a surprisingly promising platform for creating distinct Majorana zero modes in magnetic vortices in a single material and at relatively high temperatures. The magnetic field-induced Abrikosov vortex lattice makes it difficult to braid a set of Majorana zero modes or to study the coupling of a Majorana doublet due to overlapping wave functions. Here we report the observation of the proposed quantum anomalous vortex with integer quantized vortex core states and the Majorana zero mode induced by magnetic Fe adatoms deposited on the surface. We observe its hybridization with a nearby field-induced Majorana vortex in iron-based superconductor FeTe_0.55Se_0.45. We also observe vortex-free Yu-Shiba-Rusinov bound states at the Fe adatoms with a weaker coupling to the substrate, and discover a reversible transition between Yu-Shiba-Rusinov states and Majorana zero mode by manipulating the exchange coupling strength. The dual origin of the Majorana zero modes, from magnetic adatoms and external magnetic field, provides a new single-material platform for studying their interactions and braiding in superconductors bearing topological band structures.

Authors:

Fan, Peng ^[1]; Yang, Fazhi ^[1]; Qian, Guojian ^[1]; Chen, Hui  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-3369-8113"

Zhang, Yu-Yang  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-9548-0021"

Li, Geng  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-3347-7222"

Huang, Zihao ^[1]; Xing, Yuqing  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-8646-6631"

Kong, Lingyuan  ^[1];

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Liu, Wenyao  ^[1];

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Jiang, Kun ^[4]; Shen, Chengmin ^[3]; Du, Shixuan ^[3]; Schneeloch, John ^[5]; Zhong, Ruidan ^[5]; Gu, Genda ^[5]; Wang, Ziqiang ^[6]; Ding, Hong  ^[7];

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• Search DOE PAGES for ORCID "0000-0003-4422-9248"

Gao, Hong-Jun  ^[8]

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• Search DOE PAGES for ORCID "0000-0001-9323-1307"

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+ Show Author Affiliations

1. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Univ. of Chinese Academy of Sciences, Beijing (China)
2. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Univ. of Chinese Academy of Sciences, Beijing (China); Songshan Lake Materials Lab., Dongguan (China)
3. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Univ. of Chinese Academy of Sciences, Beijing (China); Univ. of Chinese Academy of Sciences, Beijing (China). CAS Center for Excellence in Topological Quantum Computation
4. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Boston College, Boston, MA (United States)
5. Brookhaven National Lab. (BNL), Upton, NY (United States)
6. Boston College, Boston, MA (United States)
7. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Songshan Lake Materials Lab., Dongguan (China); Univ. of Chinese Academy of Sciences, Beijing (China). CAS Center for Excellence in Topological Quantum Computation
8. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics. Beijing National Lab. for Condensed Matter Physics (BNLCP-CAS); Univ. of Chinese Academy of Sciences, Beijing (China); Songshan Lake Materials Lab., Dongguan (China); Univ. of Chinese Academy of Sciences, Beijing (China). CAS Center for Excellence in Topological Quantum Computation

Publication Date:

Mon Mar 01 00:00:00 EST 2021

Research Org.:

Brookhaven National Laboratory (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Natural Science Foundation of China (NSFC); National Key R&D Projects of China; Chinese Academy of Sciences

OSTI Identifier:

1781513

Report Number(s):

BNL-221355-2021-JAAM
Journal ID: ISSN 2041-1723; TRN: US2209919

Grant/Contract Number:  

SC0012704; FG02-99ER45747; 11888101; 61888102; 11674371; 52022105; 2016YFA0202300; 2018YFA0305800; 2019YFA0308500; XDB28000000; XDB07000000; 112111KYSB20160061

Resource Type:

Accepted Manuscript

Journal Name:

Nature Communications

Additional Journal Information:

Journal Volume: 12; Journal Issue: 1; Journal ID: ISSN 2041-1723

Publisher:

Nature Publishing Group

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Superconducting properties and materials; surfaces, interfaces and thin films; topological defects