Fig. 14.

a Dashed lines represent the potential profile in Region ℓ under the boundary condition of ${\left.{\varphi }_{\mathrm{\ell s}}\right|}_{x=-\infty }=0$ and the potential profile in Region r under the boundary condition of ${\left.{\varphi }_{rs}\right|}_{x=+\infty }=0$ b Potential profile expected under the boundary condition of ${\left.{\varphi }_{rs}\right|}_{x=+\infty }=0$