Back to Search
Start Over
Topological acoustic triple point
- Source :
- Nature Communications, Vol 12, Iss 1, Pp 1-9 (2021), Nature Communications
- Publication Year :
- 2021
- Publisher :
- Springer Science and Business Media LLC, 2021.
-
Abstract
- Acoustic phonon is a classic example of triple degeneracy point in band structure. This triple point always appears in phonon spectrum because of the Nambu–Goldstone theorem. Here, we show that this triple point can carry a topological charge \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathfrak{q}}$$\end{document}q that is a property of three-band systems with space-time-inversion symmetry. The charge \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathfrak{q}}$$\end{document}q can equivalently be characterized by the skyrmion number of the longitudinal mode, or by the Euler number of the transverse modes. We call triple points with nontrivial \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathfrak{q}}$$\end{document}q the topological acoustic triple point (TATP). TATP can also appear at high-symmetry momenta in phonon and spinless electron spectrums when Oh or Th groups protect it. The charge \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathfrak{q}}$$\end{document}q constrains the nodal structure and wavefunction texture around TATP, and can induce anomalous thermal transport of phonons and orbital Hall effect of electrons. Gapless points protected by the Nambu–Goldstone theorem form a new platform to study the topology of band degeneracies.<br />The topological characteristics of acoustic phonons with triple degeneracy remain largely unexplored. Here, the authors propose a topological acoustic triple point characterized by a topological charge in a three-band system with PT symmetry.
- Subjects :
- Electronic properties and materials
Phonon
Triple point
Science
FOS: Physical sciences
General Physics and Astronomy
Topology
Computer Science::Digital Libraries
Article
General Biochemistry, Genetics and Molecular Biology
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Topological insulators
Wave function
Topological quantum number
Physics
Condensed Matter - Materials Science
Multidisciplinary
Condensed Matter - Mesoscale and Nanoscale Physics
Texture (cosmology)
Skyrmion
Materials Science (cond-mat.mtrl-sci)
Charge (physics)
General Chemistry
Computer Science::Mathematical Software
Degeneracy (mathematics)
Subjects
Details
- ISSN :
- 20411723
- Volume :
- 12
- Database :
- OpenAIRE
- Journal :
- Nature Communications
- Accession number :
- edsair.doi.dedup.....0643bd824c8622804e88d88e8fc1e609