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Title: Imaging emergent heavy Dirac fermions of a topological Kondo insulator

Abstract

The interplay between strong electron interactions and band topology is a new frontier in the search for exotic quantum phases. The Kondo insulator SmB 6 has emerged as a promising platform because its correlation-driven bulk gap is predicted to host topological surface modes entangled with f electrons, spawning heavy Dirac fermions. Unlike the conventional surface states of non-interacting topological insulators, heavy Dirac fermions are expected to harbour spontaneously generated quantum anomalous Hall states, non-Abelian quantum statistics, fractionalization and topological order. Yet, the small energy scales required to probe heavy Dirac fermions have complicated their experimental realization. Here we use high-energy-resolution spectroscopic imaging in real and momentum space on SmB 6. On cooling below 35 K, we observe the opening of an insulating gap that expands to 14 meV at 2 K. Within the gap, we image the formation of linearly dispersing surface states with effective masses reaching 410 ± 20 m e (where me is the mass of the electron). Our findings demonstrate the presence of correlation-driven heavy surface states in SmB 6, in agreement with theoretical predictions. Their high effective mass translates to a large density of states near zero energy, which magnifies their susceptibility to the anticipated novelmore » orders and their potential utility.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2];  [1];  [1];  [1];  [3];  [3];  [4];  [4]; ORCiD logo [5];  [5]; ORCiD logo [6]; ORCiD logo [1]; ORCiD logo [1]
  1. Harvard Univ., Cambridge, MA (United States)
  2. Harvard Univ., Cambridge, MA (United States); Ministry of Trade and Industry (Singapore)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. Univ. of California, Irvine, CA (United States)
  5. Univ. of Maryland, College Park, MD (United States)
  6. Univ. of Illinois, Chicago, IL (United States)
Publication Date:
Research Org.:
Univ. of Illinois, Chicago, IL (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES); US Air Force Office of Scientific Research (AFOSR); Gordon and Betty Moore Foundation (GBMF); National Science Foundation (NSF)
OSTI Identifier:
1618816
Alternate Identifier(s):
OSTI ID: 1735891
Report Number(s):
LA-UR-18-28712
Journal ID: ISSN 1745-2473
Grant/Contract Number:  
FG02-05ER46225; DMR-1106023; DMR-1410480; FA9550-14-1-0332; GBMF4419; 89233218CNA000001
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nature Physics
Additional Journal Information:
Journal Volume: 16; Journal Issue: 1; Journal ID: ISSN 1745-2473
Publisher:
Nature Publishing Group (NPG)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Material Science

Citation Formats

Pirie, Harris, Liu, Yu, Soumyanarayanan, Anjan, Chen, Pengcheng, He, Yang, Yee, M. M., Rosa, P. F. S., Thompson, J. D., Kim, Dae-Jeong, Fisk, Z., Wang, Xiangfeng, Paglione, Johnpierre, Morr, Dirk K., Hamidian, M. H., and Hoffman, Jennifer E. Imaging emergent heavy Dirac fermions of a topological Kondo insulator. United States: N. p., 2019. Web. doi:10.1038/s41567-019-0700-8.
Pirie, Harris, Liu, Yu, Soumyanarayanan, Anjan, Chen, Pengcheng, He, Yang, Yee, M. M., Rosa, P. F. S., Thompson, J. D., Kim, Dae-Jeong, Fisk, Z., Wang, Xiangfeng, Paglione, Johnpierre, Morr, Dirk K., Hamidian, M. H., & Hoffman, Jennifer E. Imaging emergent heavy Dirac fermions of a topological Kondo insulator. United States. https://doi.org/10.1038/s41567-019-0700-8
Pirie, Harris, Liu, Yu, Soumyanarayanan, Anjan, Chen, Pengcheng, He, Yang, Yee, M. M., Rosa, P. F. S., Thompson, J. D., Kim, Dae-Jeong, Fisk, Z., Wang, Xiangfeng, Paglione, Johnpierre, Morr, Dirk K., Hamidian, M. H., and Hoffman, Jennifer E. Mon . "Imaging emergent heavy Dirac fermions of a topological Kondo insulator". United States. https://doi.org/10.1038/s41567-019-0700-8. https://www.osti.gov/servlets/purl/1618816.
@article{osti_1618816,
title = {Imaging emergent heavy Dirac fermions of a topological Kondo insulator},
author = {Pirie, Harris and Liu, Yu and Soumyanarayanan, Anjan and Chen, Pengcheng and He, Yang and Yee, M. M. and Rosa, P. F. S. and Thompson, J. D. and Kim, Dae-Jeong and Fisk, Z. and Wang, Xiangfeng and Paglione, Johnpierre and Morr, Dirk K. and Hamidian, M. H. and Hoffman, Jennifer E.},
abstractNote = {The interplay between strong electron interactions and band topology is a new frontier in the search for exotic quantum phases. The Kondo insulator SmB6 has emerged as a promising platform because its correlation-driven bulk gap is predicted to host topological surface modes entangled with f electrons, spawning heavy Dirac fermions. Unlike the conventional surface states of non-interacting topological insulators, heavy Dirac fermions are expected to harbour spontaneously generated quantum anomalous Hall states, non-Abelian quantum statistics, fractionalization and topological order. Yet, the small energy scales required to probe heavy Dirac fermions have complicated their experimental realization. Here we use high-energy-resolution spectroscopic imaging in real and momentum space on SmB6. On cooling below 35 K, we observe the opening of an insulating gap that expands to 14 meV at 2 K. Within the gap, we image the formation of linearly dispersing surface states with effective masses reaching 410 ± 20 me (where me is the mass of the electron). Our findings demonstrate the presence of correlation-driven heavy surface states in SmB6, in agreement with theoretical predictions. Their high effective mass translates to a large density of states near zero energy, which magnifies their susceptibility to the anticipated novel orders and their potential utility.},
doi = {10.1038/s41567-019-0700-8},
url = {https://www.osti.gov/biblio/1618816}, journal = {Nature Physics},
issn = {1745-2473},
number = 1,
volume = 16,
place = {United States},
year = {2019},
month = {11}
}

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    Works referencing / citing this record:

    Microwave Meissner screening properties of proximity-coupled topological-insulator / superconductor bilayers
    journal, December 2019


    Consistency between ARPES and STM measurements on SmB 6
    journal, February 2020