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Possible Excitonic Insulating Phase in Quantum-Confined Sb Nanoflakes

Journal Article


Abstract


  • In the 1960s, it was proposed that in small

    indirect band-gap materials, excitons can spontaneously form

    because the density of carriers is too low to screen the

    attractive Coulomb interaction between electrons and holes.

    The result is a novel strongly interacting insulating phase

    known as an excitonic insulator. Here we employ scanning

    tunnelling microscopy (STM) and spectroscopy (STS) to

    show that the enhanced Coulomb interaction in quantumconfined

    elemental Sb nanoflakes drives the system to the excitonic insulator state. The unique feature of the excitonic insulator,

    a charge density wave (CDW) without periodic lattice distortion, is directly observed. Furthermore, STS shows a gap induced

    by the CDW near the Fermi surface. Our observations suggest that the Sb(110) nanoflake is an excitonic insulator.

Publication Date


  • 2019

Citation


  • Li, Z., Nadeem, M., Yue, Z., Cortie, D., Fuhrer, M. & Wang, X. (2019). Possible Excitonic Insulating Phase in Quantum-Confined Sb Nanoflakes. Nano Letters, 19 (8), 4960-4964.

Scopus Eid


  • 2-s2.0-85071351597

Number Of Pages


  • 4

Start Page


  • 4960

End Page


  • 4964

Volume


  • 19

Issue


  • 8

Place Of Publication


  • United States

Abstract


  • In the 1960s, it was proposed that in small

    indirect band-gap materials, excitons can spontaneously form

    because the density of carriers is too low to screen the

    attractive Coulomb interaction between electrons and holes.

    The result is a novel strongly interacting insulating phase

    known as an excitonic insulator. Here we employ scanning

    tunnelling microscopy (STM) and spectroscopy (STS) to

    show that the enhanced Coulomb interaction in quantumconfined

    elemental Sb nanoflakes drives the system to the excitonic insulator state. The unique feature of the excitonic insulator,

    a charge density wave (CDW) without periodic lattice distortion, is directly observed. Furthermore, STS shows a gap induced

    by the CDW near the Fermi surface. Our observations suggest that the Sb(110) nanoflake is an excitonic insulator.

Publication Date


  • 2019

Citation


  • Li, Z., Nadeem, M., Yue, Z., Cortie, D., Fuhrer, M. & Wang, X. (2019). Possible Excitonic Insulating Phase in Quantum-Confined Sb Nanoflakes. Nano Letters, 19 (8), 4960-4964.

Scopus Eid


  • 2-s2.0-85071351597

Number Of Pages


  • 4

Start Page


  • 4960

End Page


  • 4964

Volume


  • 19

Issue


  • 8

Place Of Publication


  • United States