Topological semimetals, such as Dirac, Weyl, or line-node are gapless states of matter characterized by their nodal band structures and surface states. In this work, we consider layered (topologically trivial) insulating systems in $D$ dimensions that composed coupled multi-layers $d$-dimensional topological semimetals. Despite being nominal bulk insulators, show crystal defects having co-dimen...

Optical supercavity modes (superstates), i.e., hybrid emerging from the strong coupling of two an open cavity, can support ultranarrow lines in their scattering spectra associated with quasi bound states continuum (quasi-BIC). These are great interest for sensing applications as they enable compact systems unprecedented sensitivity. However, classical quasi-BIC sensors fundamentally limited by ...