Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Conductance Spectroscopy of Exfoliated Thin Flakes of NbxBi2Se3

Abstract

We study unconventional superconductivity in exfoliated single crystals of a promising three-dimensional (3D) topological superconductor candidate, Nb-doped Bi2Se3 through differential conductance spectroscopy and magneto-transport. The strong anisotropy of the critical field along the out-of-plane direction suggests that the thin exfoliated flakes are in the quasi-2D limit. Normal metal-superconductor (NS) contacts with either high or low transparencies made by depositing gold leads onto Nb-doped Bi2Se3 flakes both show significant enhancement in zero bias conductance and coherence dips at the superconducting energy gap. Such behavior is inconsistent with conventional Blonder–Tinkham–Klapwijk theory. Instead, we discuss how our results are consistent with p-wave pairing symmetry, supporting the possibility of topological superconductivity in Nb-doped Bi2Se3. Lastly, we observe signatures of multiple superconducting energy gaps, which could originate from multiple Fermi surfaces reported earlier in bulk crystals.

Authors:
ORCiD logo [1];  [2];  [3];  [4];  [3];  [3];  [4];  [4];  [4];  [4];  [5];  [4];  [3]
+ Show Author Affiliations
  1. Missouri Univ. of Science and Technology, Rolla, MO (United States); Univ. of Illinois at Urbana-Champaign, IL (United States)
  2. Univ. of Illinois at Urbana-Champaign, IL (United States); IBM Thomas J. Watson Research Center, Yorktown Heights, NY (United States)
  3. Univ. of Illinois at Urbana-Champaign, IL (United States)
  4. Missouri Univ. of Science and Technology, Rolla, MO (United States)
  5. City College of New of CUNY, New York, NY (United States); Department of Physics, Graduate Center of CUNY, New York, NY (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE; National Science Foundation (NSF)
OSTI Identifier:
1543686
Grant/Contract Number:  
DMR-1506152; HRD-1547830; DMR-1255607
Resource Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 19; Journal Issue: 1; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; chemistry; science & technology; other topics; Materials Science; physics; topological superconductivity; doped topological insulators; exfoliated NbxBi2Se3; p-wave pairing symmetry; Andreev reflection spectroscopy; Majorana bound states; group theory; superconductors; magnetic properties; energy; electrical conductivity

Citation Formats

Kurter, C., Finck, A. D. K., Huemiller, E. D., Medvedeva, J., Weis, A., Atkinson, J. M., Qiu, Y., Shen, L., Lee, S. H., Vojta, T., Ghaemi, P., Hor, Y. S., and Van Harlingen, D. J. Conductance Spectroscopy of Exfoliated Thin Flakes of NbxBi2Se3. United States: N. p., 2018. Web. doi:10.1021/acs.nanolett.8b02954.
Copy to clipboard
Kurter, C., Finck, A. D. K., Huemiller, E. D., Medvedeva, J., Weis, A., Atkinson, J. M., Qiu, Y., Shen, L., Lee, S. H., Vojta, T., Ghaemi, P., Hor, Y. S., & Van Harlingen, D. J. Conductance Spectroscopy of Exfoliated Thin Flakes of NbxBi2Se3. United States. https://doi.org/10.1021/acs.nanolett.8b02954
Copy to clipboard
Kurter, C., Finck, A. D. K., Huemiller, E. D., Medvedeva, J., Weis, A., Atkinson, J. M., Qiu, Y., Shen, L., Lee, S. H., Vojta, T., Ghaemi, P., Hor, Y. S., and Van Harlingen, D. J. Tue . "Conductance Spectroscopy of Exfoliated Thin Flakes of NbxBi2Se3". United States. https://doi.org/10.1021/acs.nanolett.8b02954. https://www.osti.gov/servlets/purl/1543686.
Copy to clipboard
@article{osti_1543686,
title = {Conductance Spectroscopy of Exfoliated Thin Flakes of NbxBi2Se3},
author = {Kurter, C. and Finck, A. D. K. and Huemiller, E. D. and Medvedeva, J. and Weis, A. and Atkinson, J. M. and Qiu, Y. and Shen, L. and Lee, S. H. and Vojta, T. and Ghaemi, P. and Hor, Y. S. and Van Harlingen, D. J.},
abstractNote = {We study unconventional superconductivity in exfoliated single crystals of a promising three-dimensional (3D) topological superconductor candidate, Nb-doped Bi2Se3 through differential conductance spectroscopy and magneto-transport. The strong anisotropy of the critical field along the out-of-plane direction suggests that the thin exfoliated flakes are in the quasi-2D limit. Normal metal-superconductor (NS) contacts with either high or low transparencies made by depositing gold leads onto Nb-doped Bi2Se3 flakes both show significant enhancement in zero bias conductance and coherence dips at the superconducting energy gap. Such behavior is inconsistent with conventional Blonder–Tinkham–Klapwijk theory. Instead, we discuss how our results are consistent with p-wave pairing symmetry, supporting the possibility of topological superconductivity in Nb-doped Bi2Se3. Lastly, we observe signatures of multiple superconducting energy gaps, which could originate from multiple Fermi surfaces reported earlier in bulk crystals.},
doi = {10.1021/acs.nanolett.8b02954},
journal = {Nano Letters},
number = 1,
volume = 19,
place = {United States},
year = {Tue Nov 27 00:00:00 EST 2018},
month = {Tue Nov 27 00:00:00 EST 2018}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1021/acs.nanolett.8b02954
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science
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:

Gate-tuned normal and superconducting transport at the surface of a topological insulator
journal, September 2011

  • Sacépé, Benjamin; Oostinga, Jeroen B.; Li, Jian
  • Nature Communications, Vol. 2, Issue 1
  • DOI: 10.1038/ncomms1586

Unconventional Josephson Effect in Hybrid Superconductor-Topological Insulator Devices
journal, July 2012

Josephson supercurrent through a topological insulator surface state
journal, February 2012

  • Veldhorst, M.; Snelder, M.; Hoek, M.
  • Nature Materials, Vol. 11, Issue 5
  • DOI: 10.1038/nmat3255

Symmetry protected Josephson supercurrents in three-dimensional topological insulators
journal, April 2013

  • Cho, Sungjae; Dellabetta, Brian; Yang, Alina
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms2701

Dynamical gate-tunable supercurrents in topological Josephson junctions
journal, July 2014

Signature of a topological phase transition in the Josephson supercurrent through a topological insulator
journal, January 2016

Evidence for an anomalous current–phase relation in topological insulator Josephson junctions
journal, June 2015

  • Kurter, C.; Finck, A. D. K.; Hor, Y. S.
  • Nature Communications, Vol. 6, Issue 1
  • DOI: 10.1038/ncomms8130

Superconductivity in Cu x Bi 2 Se 3 and its Implications for Pairing in the Undoped Topological Insulator
journal, February 2010

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

Superconductivity with Topological Surface State in Sr x Bi 2 Se 3
journal, August 2015

  • Liu, Zhongheng; Yao, Xiong; Shao, Jifeng
  • Journal of the American Chemical Society, Vol. 137, Issue 33
  • DOI: 10.1021/jacs.5b06815

Absence of zero-energy surface bound states in Cu x Bi 2 Se 3 studied via Andreev reflection spectroscopy
journal, July 2013

Majorana Fermions and Exotic Surface Andreev Bound States in Topological Superconductors: Application to Cu x Bi 2 Se 3
journal, March 2012

Teoria simmetrica dell’elettrone e del positrone
journal, April 1937

Majorana returns
journal, September 2009

Spin-rotation symmetry breaking in the superconducting state of CuxBi2Se3
journal, May 2016

  • Matano, K.; Kriener, M.; Segawa, K.
  • Nature Physics, Vol. 12, Issue 9
  • DOI: 10.1038/nphys3781

Time-reversal and rotation symmetry breaking superconductivity in Dirac materials
journal, May 2017

Superconductivity-induced ferromagnetism and Weyl superconductivity in Nb-doped Bi 2 Se 3
journal, May 2017

Rotational Symmetry Breaking in a Trigonal Superconductor Nb-doped Bi 2 Se 3
journal, January 2017

Scanning tunneling spectroscopy investigations of superconducting-doped topological insulators: Experimental pitfalls and results
journal, August 2018

Low-energy excitations and non-BCS superconductivity in Nb x − Bi 2 Se 3
journal, September 2018

Multiple Fermi surfaces in superconducting Nb-doped Bi 2 Se 3
journal, July 2016

Theory of tunneling conductance and surface-state transition in superconducting topological insulators
journal, May 2012

Theory of tunneling spectroscopy in superconducting Sr 2 RuO 4
journal, October 1997

  • Yamashiro, Masashi; Tanaka, Yukio; Kashiwaya, Satoshi
  • Physical Review B, Vol. 56, Issue 13
  • DOI: 10.1103/PhysRevB.56.7847

Theory of Tunneling Conductance for Normal Metal/Insulator/ Triplet Superconductor Junction
journal, September 1998

  • Yamashiro, Masashi; Tanaka, Yukio; Tanuma, Yasunari
  • Journal of the Physical Society of Japan, Vol. 67, Issue 9
  • DOI: 10.1143/JPSJ.67.3224

Superconducting proximity effect in three-dimensional topological insulators in the presence of a magnetic field
journal, November 2015

Role of critical current on the point-contact Andreev reflection spectra between a normal metal and a superconductor
journal, April 2004

Investigation of the two-gap superconductivity in a few-layer NbSe 2 -graphene heterojunction
journal, February 2018

Andreev reflection near the Dirac point at the graphene- NbSe 2 junction
journal, December 2016

Tunneling at ν T = 1 in quantum Hall bilayers
journal, October 2013

Edge States of Sr 2 RuO 4 Detected by In-Plane Tunneling Spectroscopy
journal, August 2011

Proximity Effect between Two Superconductors Spatially Resolved by Scanning Tunneling Spectroscopy
journal, March 2014

Kondo effect in a single-electron transistor
journal, January 1998

  • Goldhaber-Gordon, D.; Shtrikman, Hadas; Mahalu, D.
  • Nature, Vol. 391, Issue 6663, p. 156-159
  • DOI: 10.1038/34373

Flux-Flow Resistance in Type-II Superconductors
journal, August 1965

Phase transitions in individual sub-micrometre superconductors
journal, November 1997

  • Geim, A. K.; Grigorieva, I. V.; Dubonos, S. V.
  • Nature, Vol. 390, Issue 6657
  • DOI: 10.1038/36797

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

Majorana Modes at the Ends of Superconductor Vortices in Doped Topological Insulators
journal, August 2011

    Sort by:
    [ × clear filter / sort ]

    Works referencing / citing this record:

    Classifying Induced Superconductivity in Atomically Thin Dirac-Cone Materials
    journal, September 2019

      Sort by:
      [ × clear filter / sort ]

      Similar Records in DOE PAGES and OSTI.GOV collections: