The conceptual framework of topological states has recently been extended to bosonic systems, particularly phononic systems. In this work, we chose the recently experimentally prepared two-dimensional (2D) Kekulé-order graphene as a target to propose the coexistence of gapless and gapped topological phonon states in its phonon curves. This is the first work to investigate rich gapped and gapless topological phonon states in experimentally feasible 2D materials. For the gapped topological phonons, 2D Kekulé-order graphene hosts phononic real Chern insulator states, i.e., second-order topological states, and corner vibrational modes inside frequency gaps at 27.96 and 37.065 THz. For the gapless topological phonons, 2D Kekulé-order graphene hosts a phononic Weyl pair [comprising two linear Weyl points (LWPs)] and a phononic Weyl complex [comprising one quadratic nodal point (QNP) and two LWPs] around 7.54 and 47.3 THz (39.2 THz), respectively. Moreover, the difference between the phononic Weyl pair and the phononic Weyl complex was investigated in detail. Our study not only promotes 2D Kekulé-order graphene as a concrete material platform for exploring the intriguing physics of phononic second-order topology but also proposes the coexistence of different categories of Weyl phonons, i.e., a Weyl complex that comprises two LWPs and one QNP, in two dimensions. Our work paves the way for new advancements in topological phononics comprising gapless and gapped topological phonons.
Skip Nav Destination
Phononic Weyl pair, phononic Weyl complex, phononic real Chern insulator state, and phononic corner modes in 2D Kekulé-order graphene
Article navigation
September 2023
Research Article|
September 05 2023
Phononic Weyl pair, phononic Weyl complex, phononic real Chern insulator state, and phononic corner modes in 2D Kekulé-order graphene
Special Collection:
New Carbon Materials
Jianghua Li
;
Jianghua Li
(Investigation, Methodology, Software)
1
School of Physical Science and Technology, Southwest University
, Chongqing 400715, China
Search for other works by this author on:
Ying Liu;
Ying Liu
(Methodology, Writing – original draft)
2
School of Materials Science and Engineering, Hebei University of Technology
, Tianjin 300130, China
Search for other works by this author on:
Jingbo Bai;
Jingbo Bai
(Writing – original draft)
1
School of Physical Science and Technology, Southwest University
, Chongqing 400715, China
Search for other works by this author on:
Chengwu Xie;
Chengwu Xie
(Writing – original draft)
3
School of Electronics & Information Engineering, Tiangong University
, Tianjin 300387, China
Search for other works by this author on:
Hongkuan Yuan
;
Hongkuan Yuan
(Investigation, Methodology)
1
School of Physical Science and Technology, Southwest University
, Chongqing 400715, China
Search for other works by this author on:
Zhenxiang Cheng
;
Zhenxiang Cheng
a)
(Conceptualization, Investigation, Software, Supervision, Writing – original draft)
4
Institute for Superconducting and Electronic Materials (ISEM), University of Wollongong
, Wollongong 2500, Australia
a)Authors to whom correspondence should be addressed: cheng@uow.edu.au; xiaotianwang@swu.edu.cn; and zhangg@ihpc.a-star.edu.sg
Search for other works by this author on:
Wenhong Wang
;
Wenhong Wang
(Writing – original draft, Writing – review & editing)
3
School of Electronics & Information Engineering, Tiangong University
, Tianjin 300387, China
Search for other works by this author on:
Xiaotian Wang
;
Xiaotian Wang
a)
(Conceptualization, Supervision, Writing – original draft, Writing – review & editing)
1
School of Physical Science and Technology, Southwest University
, Chongqing 400715, China
a)Authors to whom correspondence should be addressed: cheng@uow.edu.au; xiaotianwang@swu.edu.cn; and zhangg@ihpc.a-star.edu.sg
Search for other works by this author on:
Gang Zhang
Gang Zhang
a)
(Conceptualization, Investigation, Methodology, Supervision, Writing – original draft, Writing – review & editing)
5
Institute of High-Performance Computing, Agency for Science, Technology and Research (A*STAR)
, 138632 Singapore, Singapore
a)Authors to whom correspondence should be addressed: cheng@uow.edu.au; xiaotianwang@swu.edu.cn; and zhangg@ihpc.a-star.edu.sg
Search for other works by this author on:
a)Authors to whom correspondence should be addressed: cheng@uow.edu.au; xiaotianwang@swu.edu.cn; and zhangg@ihpc.a-star.edu.sg
Appl. Phys. Rev. 10, 031416 (2023)
Article history
Received:
May 29 2023
Accepted:
August 21 2023
Citation
Jianghua Li, Ying Liu, Jingbo Bai, Chengwu Xie, Hongkuan Yuan, Zhenxiang Cheng, Wenhong Wang, Xiaotian Wang, Gang Zhang; Phononic Weyl pair, phononic Weyl complex, phononic real Chern insulator state, and phononic corner modes in 2D Kekulé-order graphene. Appl. Phys. Rev. 1 September 2023; 10 (3): 031416. https://doi.org/10.1063/5.0159948
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionPay-Per-View Access
$40.00
348
Views
Citing articles via
Related Content
Growth and characterization of novel organic quinoline 4-nitrophenol (QNP)single crystals for frequency conversion applications
AIP Conference Proceedings (November 2020)
Resonant transport in Kekulé-distorted graphene nanoribbons
J. Appl. Phys. (February 2020)
An extended Heisenberg model for conjugated hydrocarbons. II. Kekulé basis
J. Chem. Phys. (November 2003)
Ab initio study on quartet states of non‐Kekulé‐type molecules 1,3,5‐trimethylenebenzene and 1,3,5‐triaminobenzene trication
J. Chem. Phys. (March 1994)
Singlet open-shell character of conjugated Kekulé molecules
AIP Conference Proceedings (December 2012)