The time t_x, the time τ_t, and the Büttiker–Landauer time τ_BL as a function of κ d with (a) E=0.5 a.u., (b) E=0.2 a.u., (c) E=0.1 a.u., and (d) E=0.01 a.u. The height of the potential barrier V₀=1.0 a.u. is the same in (a), (b), (c), and (d). The atomic units are used with e = m = ℏ = 1 .