# gst: apropos of degeneration, the topological degeneracy induced by twisting.

<< In recent years, twisting has emerged as a new degree of freedom that plays an increasingly important role in Bloch bands of various physical systems. However, there is currently a lack of reports on the nontrivial physics of topological degeneracy in twisted systems. >>

AA << investigated the intrinsic physical correlation between twisting and topological degeneracy. (They) found that twisting not only breaks the symmetry of the system but also introduces topological degeneracy that does not exist under the original symmetric system without twisting. >>

<< Furthermore, the topological degeneracy can be easily tuned through twisting. This new twist-induced topological degeneracy gives rise to a unique polarization-degenerate birefringent medium, wherein the twist angle acts as a novel degree of freedom for dispersion and polarization management of interface states. >> 

<< Exhibiting fascinating properties and experimental feasibilities, (AA) Letter points to new possibilities in the research of various topological physics in twisted photonics. >>️

Han Peng, Qiang Wang, et al. Topological degeneracy induced by twisting. Phys. Rev. Lett. 134, 106601. Mar 11, 2025.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.106601   arXiv: 2503.09048v1 [physics.optics]. https://arxiv.org/abs/2503.09048  

Also: degeneration, in FonT https://flashontrack.blogspot.com/search?q=degeneration   twisting, twist, in FonT   https://flashontrack.blogspot.com/search?q=twisting    https://flashontrack.blogspot.com/search?q=twist 

Keywords: gst, degeneration, twisting