engleski

The Fourier Transform STM around localized impurities

We have undertaken a theoretical investigation on the dependence of the change of the LDOS upon the properties of the impurity which scatter the electrons and the shape of the isoenergy contour. We have found analytic results for rotationally invariant impurities of various radii and isotropic electronic eigenstates. The induced oscillatory change in the LDOS is similar to the case of the one-dimensional perturbation, but the expression is a more complex sum, in which the number of relevant terms depends upon the ratio of the dimension of the impurity (radius $R$, say) and the wavelength of the electronic wavefunctions, $2\pi / k_E$.Numerical results are being used to investigate the more general case of anisotropic electron gas, and compare them to the results in the simple weak-coupling limit. Our results can be used to analyze the experimental FT-STM results and determine to which extent they mirror the Fermi contour.

Density functional theory; local density of states; impurity; electron gas

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