Tip-induced band bending by scanning tunneling spectroscopy of the states of the tip-induced quantum dot on InAs(110)

Abstract

We analyze the quantized states of the tip-induced quantum dot appearing in scanning tunneling spectroscopy (STS) on n-type InAs(110) ${(N}_{D}=2\ifmmode\times\else\texttimes\fi{}{10}^{16}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}).$ STS at negative sample bias (-200--0 mV) is used to determine the state energies. The analysis of the spectra indicates that the z-quantization leads to one or two quantized states while a ladder of states due to the lateral confinement is observed. The magnetic-field dependence (0--6 T) shows the expected splitting of the first excited state in quantitative agreement with Hartree calculations. If an ionized dopant is located in the center of the quantum dot, a reduction in energy and a change in intensity of the single-particle ground state is found, which is also in quantitative agreement with Hartree calculations. The analysis of the tip-induced states can be used to reconstruct the shape of the tip-induced band bending.