Eigenstates enhanced along unstable classical periodic orbits
Quantum number: n=8 | Scarring: visible
Quantum scars (Heller 1984): in a chaotic billiard like the Bunimovich stadium, most eigenstates are
ergodic (uniform density). However, a finite fraction show anomalous enhancement along unstable periodic
classical orbits — "scars". Shown: |ψ|² intensity computed via superposition of plane waves satisfying
stadium boundary conditions, biased along chosen orbit family.