Quantum Eraser — Delayed Choice Which-Path

Double-slit interference with which-path markers. Marking destroys fringes; erasing restores them. The coincidence (post-selected) pattern shows quantum complementarity.

Setup

Slit separation d/λ: 8 Slit width a/λ: 2.0 Which-path visibility V: 0.00 Eraser efficiency η: 0.00

Physics

Complementarity: V² + F² ≤ 1
V = path visibility
F = fringe visibility

Fringe vis F = 1.000
Path info V = 0.000
V²+F² = 1.000

Post-selection restores
fringes even after marking.

Quantum Eraser — Delayed Choice & Which-Path Information

Setup

Physics