Comment on “Effects of the localized state inside the barrier on resonant tunneling in double-barrier quantum wells”

It is shown that the split of the highest-energy peak observed by He and Gu [Phys. Rev. B 41, 2906 (1990)] in the intermediate- and strong-coupling regions, when $\mid {\Omega }_b\mid$ is very large, is only an artifact.

Figure 1

The dependence of the transmission probability peak position in energy on the strength $\mid {\Omega }_b\mid$ of the $\delta$ function. Dashed curves describe the parabolic relation between $E_b$ and ${\Omega }_b$ for the defect state. The cross points A, B, and C are defined by the condition $E_b=E_3,E_2$, and $E_1$, respectively. (a)–(c) The cases of the weak, intermediate, and strong couplings. The location of the defect layer is $3b∕4,b∕2$, and $b∕4$, respectively. All the parameters are taken the same as those in Ref. 5. (d)–(f) The corresponding logarithmic transmission probability as a function of energy at $\Omega =-10\mathrm{eV}\mathrm{\AA }$, respectively.

Figure 2

The same as in Fig. 1 except here both barriers were symmetrically doped.