Measuring spin and charge correlations via tunneling-current conductance fluctuations
Abstract
Scanning tunneling miscoscopy is one of the most powerful spectroscopic tools for single-electron excitations. We show that the conductance fluctuations, or noise in the conductance, of a tunneling current into an interacting electron system is dominated by density-density and spin-spin correlations. This allows one to probe two-particle properties (susceptibilities) and collective excitations by standard experimental tunneling methods. We demonstrate this theoretically, using a novel many-body calculation for the multi-center Kondo problem, including both direct and indirect exchange between magnetic atoms. An example of the two-particle correlations around a single magnetic adatom in the Kondo regime, as would be viewed by a scanning tunneling microscope, is given. The spatial dependance of the charge and spin correlations, including the formation of the Kondo cloud in the spin sector, are shown.
Cite
@article{arxiv.0902.0225,
title = {Measuring spin and charge correlations via tunneling-current conductance fluctuations},
author = {Kelly R. Patton and Hartmut Hafermann and Sergej Brener and Alexander I. Lichtenstein and Mikhail I. Katsnelson},
journal= {arXiv preprint arXiv:0902.0225},
year = {2009}
}