1,251 research outputs found
Disorder-driven exceptional lines and Fermi ribbons in tilted nodal-line semimetals
We consider the impact of disorder on the spectrum of three-dimensional
nodal-line semimetals. We show that the combination of disorder and a tilted
spectrum naturally leads to a non-Hermitian self-energy contribution that can
split a nodal line into a pair of exceptional lines. These exceptional lines
form the boundary of an open and orientable bulk Fermi ribbon in reciprocal
space on which the energy gap vanishes. We find that the orientation and shape
of such a disorder-induced bulk Fermi ribbon is controlled by the tilt
direction and the disorder properties, which can also be exploited to realize a
twisted bulk Fermi ribbon with nontrivial winding number. Our results put
forward a paradigm for the exploration of non-Hermitian topological phases of
matter.Comment: Main Text (6 pages, 2 figures) + Supplemental Material (7 pages, 1
figure
âBurkaâ in Parliament and on the Catwalk
In Europe, face veils have become the ultimate symbols of Muslim âotherness.â The (presently stalled) attempts of the Dutch government to introduce a burka-ban highlight how misguided arguments about women's emancipation and national security are used to push a strongly assimilationist agenda. Ironically, while politicians hold on to a singly negative view of face-veils, trends in the fashion industry show that the boundaries between religion, fashion, and everyday social life are far more flexible than the political gaze is able to capture
- âŠ