Thick-barrier transmission prefactor
= Thick-barrier transmission prefactor
{title2=$T\simeq16E(U-E)U^{-2}e^{-2\kappa a}$}
For a thick rectangular barrier with equal exterior potentials, constant <mass> and $0<E<U$, the exact matched <transmission probability> has the displayed limit when $\kappa a\gg1$. The exponential is fixed by the evanescent <action>; the interface prefactor remains energy-dependent. A leading-exponential estimate can therefore differ by an order-one multiplier from the matched result.