Quantum tunnelling simulation

Can a quantum particle pass through a barrier taller than its own energy — a wall it classically could never cross?

▶ Run the simulationSee the measured result

Units: transmission probability T at E = 2.88, V₀ = 3.2, a = 1.6 (κ = 0.8 exactly, κa = 1.28)

How the lab tests it

Launch a Gaussian wavepacket at a potential barrier with energy E < V₀ and evolve the Schrödinger equation (Visscher's norm-conserving scheme); measure the probability T that ends up beyond the barrier, and compare to the rectangular-barrier formula.

What it checks

T > 0 (classically T = 0 for E < V₀ — the particle always bounces) matching the tunnelling coefficient, while the total probability ∫|ψ|² stays 1 (unitary evolution)