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SYNA: Carbon Nanotubes

SYNA 2: Poster

SYNA 2.6: Poster

Thursday, March 30, 2000, 13:30–16:00, A

Image potential in STM-setups for Luttinger liquids        — •S. Hügle¹, R. Egger^1,2, and H. Grabert¹ — ¹Fakultät für Physik, Universität Freiburg — ²Institute for Theoretical Physics, Santa Barbara, CA 93106-4030, USA

We investigate the problem of electron tunneling from a STM-tip into the bulk of a one-dimensional (1D) conductor. In the presence of a screening gate the fermions are adequately described in the framework of Luttinger liquid (LL) theory. We also consider extensions accounting for long range interactions in unscreened conductors. Using a generalized WKB-ansatz, we include the interaction between the LL and the external electron (dynamic image potential) in our calculations, as well as the finite traversal time of the tunneling electron. Although the static image potential between an external electron and a LL is very strong (only logarithmically suppressed against 1/distance), the effect of the dynamic image potential is not strong enough to alter the power law exponent of the tunneling density of states. For a simple separable model interaction, we are able to show this analytically, while in the realistic case of Coulomb interactions this is demonstrated numerically.