skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Observation of topological superconductivity on the surface of an iron-based superconductor

Abstract

Topological superconductors are predicted to host exotic Majorana states that obey non-Abelian statistics and can be used to implement a topological quantum computer. Most of the proposed topological superconductors are realized in difficult-to-fabricate heterostructures at very low temperatures. By using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe 1–xSe x (x = 0.45; superconducting transition temperature T c = 14.5 kelvin) hosts Dirac-cone–type spin-helical surface states at the Fermi level; the surface states exhibit an s-wave superconducting gap below T c. Thus, our study shows that the surface states of FeTe 0.55Se 0.45 are topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [5]; ORCiD logo [1]
+ Show Author Affiliations
  1. Univ. of Tokyo (Japan). Inst. for Solid State Physics
  2. Princeton Univ., NJ (United States). Dept. of Physics
  3. Nanjing Univ. (China). National Lab. of Solid State Microstructures and Dept. of Physics
  4. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
  5. 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 (CAS), Beijing (China). CAS Center for Excellence in Topological Quantum Computation
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; Ministry of Education, Culture, Sports, Science and Technology (MEXT); Japan Society for the Promotion of Science (JSPS); National Natural Science Foundation of China (NNSFC); Ministry of Science and Technology (MOST); Chinese Academy of Sciences (CAS)
OSTI Identifier:
1440897
Report Number(s):
BNL-205750-2018-JAAM
Journal ID: ISSN 0036-8075
Grant/Contract Number:  
SC0012704; 25220707; 16H02209; 16H06013; 16H00979; 11234014; 11504117; 2016YFA0401000; 2015CB921300; XDPB08-1; XDB07000000
Resource Type:
Accepted Manuscript
Journal Name:
Science
Additional Journal Information:
Journal Volume: 360; Journal Issue: 6385; Journal ID: ISSN 0036-8075
Publisher:
AAAS
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 97 MATHEMATICS AND COMPUTING

Citation Formats

Zhang, Peng, Yaji, Koichiro, Hashimoto, Takahiro, Ota, Yuichi, Kondo, Takeshi, Okazaki, Kozo, Wang, Zhijun, Wen, Jinsheng, Gu, G. D., Ding, Hong, and Shin, Shik. Observation of topological superconductivity on the surface of an iron-based superconductor. United States: N. p., 2018. Web. doi:10.1126/science.aan4596.
Copy to clipboard
Zhang, Peng, Yaji, Koichiro, Hashimoto, Takahiro, Ota, Yuichi, Kondo, Takeshi, Okazaki, Kozo, Wang, Zhijun, Wen, Jinsheng, Gu, G. D., Ding, Hong, & Shin, Shik. Observation of topological superconductivity on the surface of an iron-based superconductor. United States. doi:10.1126/science.aan4596.
Copy to clipboard
Zhang, Peng, Yaji, Koichiro, Hashimoto, Takahiro, Ota, Yuichi, Kondo, Takeshi, Okazaki, Kozo, Wang, Zhijun, Wen, Jinsheng, Gu, G. D., Ding, Hong, and Shin, Shik. Thu . "Observation of topological superconductivity on the surface of an iron-based superconductor". United States. doi:10.1126/science.aan4596. https://www.osti.gov/servlets/purl/1440897.
Copy to clipboard
@article{osti_1440897,
title = {Observation of topological superconductivity on the surface of an iron-based superconductor},
author = {Zhang, Peng and Yaji, Koichiro and Hashimoto, Takahiro and Ota, Yuichi and Kondo, Takeshi and Okazaki, Kozo and Wang, Zhijun and Wen, Jinsheng and Gu, G. D. and Ding, Hong and Shin, Shik},
abstractNote = {Topological superconductors are predicted to host exotic Majorana states that obey non-Abelian statistics and can be used to implement a topological quantum computer. Most of the proposed topological superconductors are realized in difficult-to-fabricate heterostructures at very low temperatures. By using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe1–xSex (x = 0.45; superconducting transition temperature Tc = 14.5 kelvin) hosts Dirac-cone–type spin-helical surface states at the Fermi level; the surface states exhibit an s-wave superconducting gap below Tc. Thus, our study shows that the surface states of FeTe0.55Se0.45 are topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.},
doi = {10.1126/science.aan4596},
journal = {Science},
number = 6385,
volume = 360,
place = {United States},
year = {2018},
month = {3}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI:  10.1126/science.aan4596
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 49 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Band structure and topological superconductivity of FeTe0.5Se0.5. (A) Crystal structure of Fe(Te,Se), together with the 3D BZ and projected surface BZ. (B) In-plane BZ at kz = 0. There are two hole-like FSs at Γ and two electron-like FSs at M. The dashed circle at Γ indicates themore » hole-like band just below EF. (C) First-principles calculations on band structure along the ΓM direction, as indicated by the light blue line in (B). In the calculations, t = 100 meV, while t ~ 12 - 25 meV from experiments, largely depending on the bands (27). In this study, we focus on the small area around Γ with light blue background, where mainly dxz band is present. (D) Firstprinciples calculations on band structure along ΓM and ΓZ. The dashed box shows the SOC gap of the inverted bands. (E) Band structure projected onto the (001) surface. The topological surface states (TSS) between the bulk valence band (BVB) and bulk conduction band (BCB) is clearly shown in this plot. (F) When the temperature decreases to below Tc, the bulk bands open s-wave SC gaps, which induce the surface states to be superconducting. The spin-helical surface states thus become topologically superconducting. (The side surface is shown for convenience.)« less
All figures and tables (5 total)
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

Topological insulators and superconductors
journal, October 2011

Spin-Orbit Interactions and the Nematicity Observed in the Fe-Based Superconductors
journal, April 2015

Odd-Parity Topological Superconductors: Theory and Application to Cu x Bi 2 Se 3
journal, August 2010

Topological Superconductivity in Cu x Bi 2 Se 3
journal, November 2011

Topological nature of the FeSe 0.5 Te 0.5 superconductor
journal, September 2015

Topological Superconductivity on the Surface of Fe-Based Superconductors
journal, July 2016

Momentum-space imaging of Cooper pairing in a half-Dirac-gas topological superconductor
journal, November 2014

  • Xu, Su-Yang; Alidoust, Nasser; Belopolski, Ilya
  • Nature Physics, Vol. 10, Issue 12
  • DOI: 10.1038/nphys3139

Majorana Zero Mode Detected with Spin Selective Andreev Reflection in the Vortex of a Topological Superconductor
journal, June 2016

Signatures of Majorana Fermions in Hybrid Superconductor-Semiconductor Nanowire Devices
journal, April 2012

A precise method for visualizing dispersive features in image plots
journal, April 2011

  • Zhang, P.; Richard, P.; Qian, T.
  • Review of Scientific Instruments, Vol. 82, Issue 4
  • DOI: 10.1063/1.3585113

Observation of a robust zero-energy bound state in iron-based superconductor Fe(Te,Se)
journal, June 2015

  • Yin, J-X.; Wu, Zheng; Wang, J-H.
  • Nature Physics, Vol. 11, Issue 7
  • DOI: 10.1038/nphys3371

Inhomogeneous Electron Gas
journal, November 1964

First Investigation of Pressure Effects on Transition from Superconductive to Metallic Phase in FeSe 0.5 Te 0.5
journal, June 2009

  • Horigane, Kazumasa; Takeshita, Nao; Lee, Chul-Ho
  • Journal of the Physical Society of Japan, Vol. 78, Issue 6
  • DOI: 10.1143/JPSJ.78.063705

FeTe 1− x Se x monolayer films: towards the realization of high-temperature connate topological superconductivity
journal, April 2017

Non-Abelian anyons and topological quantum computation
journal, September 2008

Calculated cleavage behavior and surface states of LaOFeAs
journal, April 2010

Exponential protection of zero modes in Majorana islands
journal, March 2016

  • Albrecht, S. M.; Higginbotham, A. P.; Madsen, M.
  • Nature, Vol. 531, Issue 7593
  • DOI: 10.1038/nature17162

Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe 0.55 Se 0.45
journal, March 2012

Superconducting Proximity Effect and Majorana Fermions at the Surface of a Topological Insulator
journal, March 2008

Interface-enhanced high-temperature superconductivity in single-unit-cell FeT e 1 − x S e x films on SrTi O 3
journal, June 2015

Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
journal, February 2014

  • Okazaki, K.; Ito, Y.; Ota, Y.
  • Scientific Reports, Vol. 4, Issue 1
  • DOI: 10.1038/srep04109

Spin fluctuations and superconductivity in a three-dimensional tight-binding model for BaFe 2 As 2
journal, June 2010

Spin–orbit-induced photoelectron spin polarization in angle-resolved photoemission from both atomic and condensed matter targets
journal, April 2012

Observation of Majorana fermions in ferromagnetic atomic chains on a superconductor
journal, October 2014

Shallow pockets and very strong coupling superconductivity in FeSexTe1−x
journal, February 2012

  • Lubashevsky, Y.; Lahoud, E.; Chashka, K.
  • Nature Physics, Vol. 8, Issue 4
  • DOI: 10.1038/nphys2216

Topological characters in Fe ( Te 1 − x Se x ) thin films
journal, March 2016

First-order magnetic and structural phase transitions in Fe 1 + y Se x Te 1 − x
journal, February 2009

Electronic structure of Fe 1.04 Te 0.66 Se 0.34
journal, January 2010

Photoelectron spin-flipping and texture manipulation in a topological insulator
journal, March 2013

  • Jozwiak, Chris; Park, Cheol-Hwan; Gotlieb, Kenneth
  • Nature Physics, Vol. 9, Issue 5
  • DOI: 10.1038/nphys2572

High-resolution three-dimensional spin- and angle-resolved photoelectron spectrometer using vacuum ultraviolet laser light
journal, May 2016

  • Yaji, Koichiro; Harasawa, Ayumi; Kuroda, Kenta
  • Review of Scientific Instruments, Vol. 87, Issue 5
  • DOI: 10.1063/1.4948738

Imaging atomic-scale effects of high-energy ion irradiation on superconductivity and vortex pinning in Fe(Se,Te)
journal, May 2015

  • Massee, Freek; Sprau, Peter Oliver; Wang, Yong-Lei
  • Science Advances, Vol. 1, Issue 4
  • DOI: 10.1126/sciadv.1500033

Structural distortion and magnetism in transition metal oxides: crucial roles of orbital degrees of freedom
journal, March 2002

Maximally localized Wannier functions for entangled energy bands
journal, December 2001

Observation of an electron band above the Fermi level in FeTe0.55Se0.45 from in-situ surface doping
journal, October 2014

  • Zhang, P.; Richard, P.; Xu, N.
  • Applied Physics Letters, Vol. 105, Issue 17
  • DOI: 10.1063/1.4900870

Octet-Line Node Structure of Superconducting Order Parameter in KFe2As2
journal, September 2012

The puzzle of high temperature superconductivity in layered iron pnictides and chalcogenides
journal, October 2010

Self-Consistent Equations Including Exchange and Correlation Effects
journal, November 1965

    [ × clear filter / sort ]

    Figures / Tables found in this record:

    Figure 1(p. 8)figure
    Figure 2(p. 9)figure
    Figure 3(p. 10)figure
    Figure 4(p. 11)figure
    Figure 5(p. 12)figure
      [ × clear filter / sort ]
      Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

      Similar records in OSTI.GOV collections: