Nodal-Line Semimetal: Drumhead Surface States
Interactive 3D k-space model of a nodal-line semimetal: a ring of gapless Dirac points threading the Brillouin zone, the flat 'drumhead' surface band it protects, and a numerically computed Berry phase pinned to pi around the ring.
Most band-touching points in solids are isolated — a single Dirac or Weyl node. A nodal-line semimetal is different: its conduction and valence bands cross along a whole closed ring threaded through the Brillouin zone. This simulator renders that ring from a real two-band k·p Hamiltonian, shows the bulk energy gap as a crater-shaped surface that touches zero exactly on the ring, and reveals the flat "drumhead" surface band it protects on any slab cut through the ring's interior. A discretized Wilson-loop calculation confirms the topological fingerprint directly: the Berry phase picked up by a loop encircling the ring stays pinned at π no matter how the ring radius or dispersion parameters are tuned.
An interactive k-space model of a nodal-line semimetal, where conduction and valence bands touch along a closed ring rather than an isolated point, protecting a flat 'drumhead' surface band and a Berry phase pinned to pi.
3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install