Wentzel-Kramers-Brillouin (WKB) semiclassical expansion. Setup: stationary 1D Schrodinger equation -hbar^2/(2m) psi'' + V(x) psi = E psi. Ansatz psi(x) = exp(i S(x)/hbar) with S expanded in powers of hbar: S = S_0 + hbar S_1 + hbar^2 S_2 +…
Wentzel-Kramers-Brillouin (WKB) semiclassical expansion. Setup: stationary 1D Schrodinger equation -hbar^2/(2m) psi'' + V(x) psi = E psi. Ansatz psi(x) = exp(i S(x)/hbar) with S expanded in powers of hbar: S = S_0 + hbar S_1 + hbar^2 S_2 +…