English
Related papers

Related papers: Triple point fermions in ferroelectric GeTe

200 papers

Multipolar orderings in degenerate orbital systems offer unique opportunities for emergent topological phases. The phase diagram of interacting spinless fermions in a $p$-band diamond lattice at unit filling is first studied to elucidate…

Strongly Correlated Electrons · Physics 2022-06-08 Hua Chen , Congjun Wu , X. C. Xie

Using a well-focused soft X-ray synchrotron radiation beam, angle-resolved photoelectron spectroscopy was applied to a full-Heusler-type Co$_2$MnGe alloy to elucidate its bulk band structure. A large parabolic band at the Brillouin zone…

When band degeneracy occurs in a spin-split band structure, it gives rise to divergent Berry curvature and distinctive topological boundary states, resulting in a variety of fascinating effects. We show that three-dimensional spin-split…

Mesoscale and Nanoscale Physics · Physics 2026-02-18 Zheng-Yang Zhuang , Di Zhu , Zhigang Wu , Zhongbo Yan

In the new van der Waals Kondo-lattice Fe$_3$GeTe$_2$, itinerant ferromagnetism and heavy fermionic behaviour coexist. Both the key properties of such a system namely a spin-polarized Fermi surface and a low Fermi momentum are expected to…

Topologically protected fermionic quasiparticles appear in metals, where band degeneracies occur at the Fermi level, dictated by the band structure topology. While in some metals these quasiparticles are direct analogues of elementary…

Mesoscale and Nanoscale Physics · Physics 2016-07-11 Ziming Zhu , Georg W. Winkler , QuanSheng Wu , Ju Li , Alexey A. Soluyanov

We report electronic band structure calculations for Sr$_{4}$Ru$_{3}$O$_{10}$ that displays both ferromagnetic and metamagnetic behavior. The density functional calculations find the ground state to be ferromagnetic in agreement with the…

Strongly Correlated Electrons · Physics 2022-04-27 G. Gebreyesus , Prosper Ngabonziza , Jonah Nagura , Nicola Seriani , Omololu Akin-Ojo , Richard M. Martin

Similar to Weyl fermions, a recently discovered topological fermion "triple point" can be generated from the splitting of Dirac fermion while the system has inversion symmetry (IS) breaking or time reversal symmetry (TRS) breaking. Inducing…

Mesoscale and Nanoscale Physics · Physics 2018-12-13 Chi-Ho Cheung , R. C. Xiao , Ming-Chien Hsu , Huei-Ru Fuh , Yeu-Chung Lin , Ching-Ray Chang

Band inversions are key to stabilising a variety of novel electronic states in solids, from topological surface states in inverted bulk band gaps of topological insulators to the formation of symmetry-protected three-dimensional Dirac and…

In this study, we investigate the spin texture of the hourglass fermions band network in BiInO$_3$ using density functional theory (DFT) and symmetry analysis. Hourglass fermions are of interest in spintronics due to their unique and robust…

Materials Science · Physics 2025-06-27 Ramsamoj Kewat , Nirmal Ganguli

Band topology, or global wave-function structure that enforces novel properties in the bulk and on the surface of crystalline materials, is currently under intense investigations for both fundamental interest and its technological promises.…

Mesoscale and Nanoscale Physics · Physics 2018-12-11 Weiliang Yao , Chenyuan Li , Lichen Wang , Shangjie Xue , Yang Dan , Kazuki Iida , Kazuya Kamazawa , Kangkang Li , Chen Fang , Yuan Li

In metallic condensed matter systems two different types of Weyl fermions can in principle emerge, with either a vanishing (type-I) or with a finite (type-II) density of states at the Weyl node energy. So far only WTe2 and MoTe2 were…

Strongly Correlated Electrons · Physics 2016-05-25 K. Koepernik , D. Kasinathan , D. V. Efremov , Seunghyun Khim , Sergey Borisenko , Bernd Büchner , Jeroen van den Brink

We demonstrate the existence of topologically stable unpaired exceptional points (EPs), and construct simple non-Hermitian (NH) tight-binding models exemplifying such remarkable nodal phases. While fermion doubling, i.e. the necessity of…

Mesoscale and Nanoscale Physics · Physics 2023-10-31 J. Lukas K. König , Kang Yang , Jan Carl Budich , Emil J. Bergholtz

Spin splitting and the resulting spin texture are central to emerging spintronic applications. In non-centrosymmetric non-magnetic materials containing heavy elements, spin textures are typically governed by low-order, momentum-dependent…

Materials Science · Physics 2025-07-31 Jiaxuan Wu , Boyun Zeng , Hanghui Chen

Pyrite-type PdSb$_2$ with a nonsymmorphic cubic structure has been predicted to host six-fold-degenerate exotic fermions beyond the Dirac and Weyl fermions. Though magnetotransport measurements on PdSb$_2$ suggest its topologically…

In many realistic topological materials, more than one kind of fermions contribute to the electronic bands crossing the Fermi level, leading to various novel phenomena. Here, using momentum-resolved inelastic electron scattering, we…

Materials Science · Physics 2020-10-28 Xun Jia , Maoyuan Wang , Dayu Yan , Siwei Xue , Shuyuan Zhang , Jianhui Zhou , Youguo Shi , Xuetao Zhu , Yugui Yao , Jiandong Guo

Recently, multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with nontrivial Chern numbers have been discovered experimentally in AlPt[arXiv:1812.03310] and…

Superconductivity · Physics 2022-09-26 Jason Z. S. Gao , Xue-Jian Gao , Wen-Yu He , Xiao Yan Xu , T. K. Ng , K. T. Law

The layered compound Fe3GaTe2 is attracting attention due to its high Curie temperature, low dimensionality, and the presence of topological spin textures above room temperature, making Fe$_3$GaTe$_2$ a good candidate for applications in…

In Weyl materials the valence and conduction electron bands touch at an even number of isolated points in the Brillouin zone. In the vicinity of these points the electron dispersion is linear and may be described by the massless Dirac…

Mesoscale and Nanoscale Physics · Physics 2016-05-12 Songci Li , A. V. Andreev

Recent experimental realization of long sought Weyl fermions in non-magnetic crystals has greatly motivated condensed matter physicists to search for materials supporting Weyl fermions. Weyl fermions appear to be very promising for future…

Materials Science · Physics 2017-10-26 Sobhit Singh , A. C. Garcia-Castro , Irais Valencia-Jaime , Francisco Muñoz , Aldo H. Romero

We report a study of the Fermi surface of the chiral semimetal CoSi and its relationship to a network of multifold topological crossing points,Weyl points, and topological nodal planes in the electronic band structure. Combining quantum…