STM images and STS for a rectangular quantum corral constructed with δ-function barriers and the effect of an adsorbed atom on STM images and STS

Assuming that an electron confined by double δ-function barriers is in a quasi-stationary state, we derived eigenfunctions and eigenenergies of the electron. Applying this point of view to the electron confined in a rectangular quantum corral (QC), we obtained scanning tunneling microscopic (STM) images and scanning tunneling spectrum (STS). Our results are consistent with experimental ones, which confirms validity of the present model. Comparing with the treatment in which the corral potential is chosen to be of square-barrier type, the present treatment has an advantage that the eigenvalue equations are simple and the number of parameters that specify the potential barrier is only one except the bottom of the potential well. On the basis of a Dyson equation for the Green function we calculated STM images and STS of the QC having an adsorbed atom inside. Our results are consistent with experimental STM images and STS. In contrast to a previous viewpoint that the STS profile is reversed with that of the empty QC, we concluded the STS peaks of the adsorbed QC are shifted downward from those of the empty QC.

► We calculated STM images and STS for a rectangular quantum corral. ► Our results are consistent with experimental STM images. ► We also calculated STM images and STS for the adsorbed quantum corral. ► We used a Dyson equation formalism for the Green function of the adsorbed system. ► The measured STS profile can be interpreted as that shifted downward in bias voltage.