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Related papers: Unveiling Real Triple Degeneracies in Crystals: Ex…

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We study the occurrence of symmetry-enforced topological band crossings in tetragonal crystals with strong spin-orbit coupling. By computing the momentum dependence of the symmetry eigenvalues and the global band topology in the entire…

We develop a unified view of topological phase transitions (TPTs) in solids by revising the classical band theory with the inclusion of topology. Re-evaluating the band evolution from an "atomic crystal" [a normal insulator (NI)] to a solid…

Materials Science · Physics 2020-05-11 Huaqing Huang , Feng Liu

Topological crystalline phases in electronic structures can be generally classified using the spatial symmetry characters of the valence bands and mapping them onto appropriate symmetry indicators. These mappings have been recently applied…

Mesoscale and Nanoscale Physics · Physics 2019-10-02 Sander H. Kooi , Guido van Miert , Carmine Ortix

Recent developments in topological semimetals open a way to realize relativistic dispersions in condensed matter systems. One recently studied type of topological feature is the "triple nodal point" where three bands become degenerate. In…

Materials Science · Physics 2018-10-17 Jinwoong Kim , Heung-Sik Kim , David Vanderbilt

Topological metals and semimetals (TMs) have recently drawn significant interest. These materials give rise to condensed matter realizations of many important concepts in high-energy physics, leading to wide-ranging protected properties in…

The realization of triply degenerate points (TDPs) with exotic fermionic excitations has opened a new perspective for the understanding of our nature. Here we explore the coexistence of single unpaired TDP and multiple twofold Weyl points…

Quantum Gases · Physics 2022-07-14 Zhoutao Lei , Yuangang Deng , Chaohong Lee

We study a class of topological materials which in their momentum-space band structure exhibit three-fold degeneracies known as triple points. Focusing specifically on $\mathcal{P}\mathcal{T}$-symmetric crystalline solids with negligible…

Mesoscale and Nanoscale Physics · Physics 2022-02-28 Patrick M. Lenggenhager , Xiaoxiong Liu , Stepan S. Tsirkin , Titus Neupert , Tomáš Bzdušek

We classify the band degeneracies in 3D crystals with screw symmetry $n_m$ and broken $\mathcal P*\mathcal T$ symmetry, where $\mathcal P$ stands for spatial inversion and $\mathcal T$ for time reversal. The generic degeneracies along…

Materials Science · Physics 2017-07-27 Stepan S. Tsirkin , Ivo Souza , David Vanderbilt

Weyl semimetals are gapless three-dimensional (3D) phases whose bandstructures contain Weyl point (WP) degeneracies. WPs carry topological charge and can only be eliminated by mutual annihilation, a process that generates the various…

Weyl points are the degenerate points in three-dimensional momentum space with nontrivial topological phase, which are usually realized in classical system with structure and symmetry designs. Here we proposed a one-dimensional…

Optics · Physics 2021-12-01 Ying Chen , Hai-xiao Wang , Qiaoliang Bao , Jian-Hua Jiang , Huanyang Chen

The recent discovery of topological insulators has revived interest in the topological properties of insulating band structures. In this work, we extend the topological classification of insulating band structures to include certain point…

Materials Science · Physics 2011-03-15 Liang Fu

Novel fermionic quasiparticles with integer pseudospins in some energy bands, such as pseudospin-1 triple-point fermions, recently attract increasing interest since they are beyond the conventional spin-$1/2$ Dirac and Weyl counterparts. In…

Quantum Gases · Physics 2018-11-27 Xue-Ying Mai , Yan-Qing Zhu , Zhi Li , Dan-Wei Zhang , Shi-Liang Zhu

The application of topology, a branch of mathematics, to the study of electronic states in crystalline materials has had a revolutionary impact on the field of condensed matter physics. For example, the development of topological band…

Materials Science · Physics 2023-10-19 Christopher Daggett , Kaijie Yang , Chaoxing Liu , Lukas Muechler

Weyl points are the simplest topologically-protected degeneracy in a three-dimensional dispersion relation. The realization of Weyl semimetals in photonic crystals has allowed these singularities and their consequences to be explored with…

Mesoscale and Nanoscale Physics · Physics 2020-11-23 R. L. Mc Guinness , P. R. Eastham

Effective relativistic field theory models capable of realizing various gapless topological states are presented in this work. We study the topological phase transitions of the Weyl and nodal line semimetal states in effective field…

Mesoscale and Nanoscale Physics · Physics 2024-07-08 Xuanting Ji , Ya-Wen Sun

We present a method for efficiently enumerating all allowed, topologically distinct, electronic band structures within a given crystal structure. The algorithm applies to crystals with broken time-reversal, particle-hole, and chiral…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 Jorrit Kruthoff , Jan de Boer , Jasper van Wezel , Charles L. Kane , Robert-Jan Slager

The past decades have witnessed a transformation in characterizing condensed matter systems with topology. Aided by a refined understanding of topological band structures with crystalline symmetries that has emerged recently, many…

Materials Science · Physics 2021-10-12 Lin-Lin Wang , Hoi Chun Po , Robert-Jan Slager , Ashvin Vishwanath

In PT symmetric systems, the notion of non-Abelian frame charges enables multiband topological characterization of the degeneracy nodes through examining the eigenvector frame rotations. Interestingly, some features of these frame charges…

Optics · Physics 2023-08-03 Dongyang Wang , Z. Q. Zhang , C. T. Chan

We review recent theoretical progress in the understanding and prediction of novel topological semimetals. Topological semimetals define a class of gapless electronic phases exhibiting topologically stable crossings of energy bands.…

Mesoscale and Nanoscale Physics · Physics 2019-09-04 Heng Gao , Jörn W. F. Venderbos , Youngkuk Kim , Andrew M. Rappe

Using topological band theory analysis we show that the nonsymmorphic symmetry operations in hexagonal lattices enforce Weyl points at the screw-invariant high-symmetry lines of the band structure. The corepresentation theory and…

Materials Science · Physics 2021-01-15 Rafael González-Hernández , Erick Tuiran , Bernardo Uribe