8 citations · 12 across the 5 of their papers we have counts for
4 papers · 1 filter
Second-Chern Bounds in Non-Abelian Quantum Geometry
Junwen Zhao, Zhiming Pan, Kang Yang +1
We study the quantum geometry of doubly degenerate energy levels in a four-dimensional parameter space. We find that the scalar quantum metric and the Berry curvature obey…
Spontaneous Chern-Euler Duality Transitions
Kang Yang, Zhi Li, Peng Xue +2
Topological phase transitions are typically characterized by abrupt changes in a quantized invariant. Here we report a contrasting paradigm in spontaneous parity-time symmetry-brea…
Exceptional topology on nonorientable manifolds
J. Lukas K. König, Kang Yang, André Grossi Fonseca +3
We classify gapped phases and characteristic nodal points of non-Hermitian band structures on two-dimensional nonorientable parameter spaces. Such spaces arise in a wide range of p…
Observation of Braid-Protected Unpaired Exceptional Points
Kunkun Wang, J. Lukas K. König, Kang Yang +4
Spectral degeneracies (dubbed nodal points in momentum space) play fundamental roles in understanding exotic properties of light and matter. In lattice systems, unpaired band-struc…