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arXiv · 0902.0225

Measuring spin and charge correlations via tunneling-current conductance fluctuations

Kelly R. Patton·Hartmut Hafermann·Sergej Brener·Alexander I. Lichtenstein·Mikhail I. Katsnelson
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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.

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Kelly R. Patton, Hartmut Hafermann, Sergej Brener, Alexander I. Lichtenstein, Mikhail I. Katsnelson. 2009-02-02. Measuring spin and charge correlations via tunneling-current conductance fluctuations. https://arxiv.org/abs/0902.0225

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