Publication details
Triple-Point Fermions in Ferroelectric GeTe
| Authors | |
|---|---|
| Year of publication | 2021 |
| Type | Article in Periodical |
| Magazine / Source | Physical Review Letters |
| MU Faculty or unit | |
| Citation | |
| web | https://doi.org/10.1103/PhysRevLett.126.206403 |
| Doi | http://dx.doi.org/10.1103/PhysRevLett.126.206403 |
| Keywords | Electronic structure; Ferroelectricity; Topological phases of matter; Topological materials; Angle-resolved photoemission spectroscopy; Density functional calculations |
| Description | Ferroelectric alpha-GeTe is unveiled to exhibit an intriguing multiple nontrivial topology of the electronic band structure due to the existence of triple-point and type-II Weyl fermions, which goes well beyond the giant Rashba spin splitting controlled by external fields as previously reported. Using spin- and angle-resolved photoemission spectroscopy combined with ab initio density functional theory, the unique spin texture around the triple point caused by the crossing of one spin-degenerate and two spin-split bands along the ferroelectric crystal axis is derived. This consistently reveals spin winding numbers that are coupled with time-reversal symmetry and Lorentz invariance, which are found to be equal for both triple-point pairs in the Brillouin zone. The rich manifold of effects opens up promising perspectives for studying nontrivial phenomena and multicomponent fermions in condensed matter systems. |
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