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Superconductivity in monolayer and few-layer graphene. II. Topological edge states and Chern numbers

Crépieux, Adeline ; Pangburn, Emile ; Haurie, Louis ; Awoga, Oladunjoye A. LU ; Black-Schaffer, Annica M. ; Sedlmayr, Nicholas ; Pépin, Catherine and Bena, Cristina (2023) In Physical Review B 108(13).
Abstract

We study the emergence of electronic edge states in superconducting
monolayer, bilayer, and trilayer graphene for both spin-singlet and
spin-triplet superconducting order parameters. We focus mostly on the
gapped chiral p+ip′- and d+id′-wave superconducting states that show a nonzero Chern number and a corresponding number of edge states. For the p+ip′-wave
state, we observe a rich phase diagram for the Chern number when tuning
the chemical potential and the superconducting order parameter
amplitude, which depends strongly on the number of layers and their
stacking and is also modified by trigonal warping. At small parameter
values, compared to hopping energy, we observe a region whose Chern
... (More)

We study the emergence of electronic edge states in superconducting
monolayer, bilayer, and trilayer graphene for both spin-singlet and
spin-triplet superconducting order parameters. We focus mostly on the
gapped chiral p+ip′- and d+id′-wave superconducting states that show a nonzero Chern number and a corresponding number of edge states. For the p+ip′-wave
state, we observe a rich phase diagram for the Chern number when tuning
the chemical potential and the superconducting order parameter
amplitude, which depends strongly on the number of layers and their
stacking and is also modified by trigonal warping. At small parameter
values, compared to hopping energy, we observe a region whose Chern
number is unique to rhombohedrally stacked graphene and is independent
of the number of layers. Our results can be understood in relation not
only to the superconducting order parameter winding as expected but also
to the normal state band structure. This observation establishes the
importance of the normal state characteristics for understanding the
topology in superconducting graphene systems.

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Please use this url to cite or link to this publication:
author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
108
issue
13
article number
134515
publisher
American Physical Society
external identifiers
  • scopus:85177024045
ISSN
2469-9950
DOI
10.1103/PhysRevB.108.134515
language
English
LU publication?
yes
id
e0b68b8e-47f8-4d3b-bb94-723f13a26b88
date added to LUP
2024-01-02 16:41:52
date last changed
2024-01-08 10:23:13
@article{e0b68b8e-47f8-4d3b-bb94-723f13a26b88,
  abstract     = {{<p>We study the emergence of electronic edge states in superconducting <br>
monolayer, bilayer, and trilayer graphene for both spin-singlet and <br>
spin-triplet superconducting order parameters. We focus mostly on the <br>
gapped chiral p+ip′- and d+id′-wave superconducting states that show a nonzero Chern number and a corresponding number of edge states. For the p+ip′-wave<br>
 state, we observe a rich phase diagram for the Chern number when tuning<br>
 the chemical potential and the superconducting order parameter <br>
amplitude, which depends strongly on the number of layers and their <br>
stacking and is also modified by trigonal warping. At small parameter <br>
values, compared to hopping energy, we observe a region whose Chern <br>
number is unique to rhombohedrally stacked graphene and is independent <br>
of the number of layers. Our results can be understood in relation not <br>
only to the superconducting order parameter winding as expected but also<br>
 to the normal state band structure. This observation establishes the <br>
importance of the normal state characteristics for understanding the <br>
topology in superconducting graphene systems.</p>}},
  author       = {{Crépieux, Adeline and Pangburn, Emile and Haurie, Louis and Awoga, Oladunjoye A. and Black-Schaffer, Annica M. and Sedlmayr, Nicholas and Pépin, Catherine and Bena, Cristina}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  month        = {{10}},
  number       = {{13}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Superconductivity in monolayer and few-layer graphene. II. Topological edge states and Chern numbers}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.108.134515}},
  doi          = {{10.1103/PhysRevB.108.134515}},
  volume       = {{108}},
  year         = {{2023}},
}