Quantum Tunneling Wave (2D)

This 2D companion drives the same finite-difference Schrödinger wave-packet evolution as the 3D version through a flat canvas view built for reading the physics directly: the cyan curve is the wave function's real part, the purple filled area is probability density, and green dots mark packet energy that made it past the barrier. Raise the barrier or drop the packet energy below it and the tunneling rate visibly thins out — the same exponential falloff behind alpha decay and scanning tunneling microscopes.