Particle energy E (eV)
3.00
Barrier height V₀ (eV)
5.00
Barrier width d (Å)
2.00
Barrier shape
T =
ln(T) =
κ₀ = Å⁻¹
∫κdx =
WKB Approximation

For E < V(x), the wavefunction decays as:
ψ ∝ exp(−∫κ(x)dx)
κ(x) = √[2m(V(x)−E)] / ℏ

Transmission: T = exp(−2∫κ dx)

Applications: alpha decay (Gamow 1928), scanning tunneling microscope, Josephson junctions, nuclear fusion in stars.