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arXiv · 0711.3370

Local Density of States in Mesoscopic Samples from Scanning Gate Microscopy

M. G. Pala·B. Hackens·F. Martins·H. Sellier·V. Bayot·S. Huant·T. Ouisse
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Abstract

We study the relationship between the local density of states (LDOS) and the conductance variation $ΔG$ in scanning-gate-microscopy experiments on mesoscopic structures as a charged tip scans above the sample surface. We present an analytical model showing that in the linear-response regime the conductance shift $ΔG$ is proportional to the Hilbert transform of the LDOS and hence a generalized Kramers-Kronig relation holds between LDOS and $ΔG$. We analyze the physical conditions for the validity of this relationship both for one-dimensional and two-dimensional systems when several channels contribute to the transport. We focus on realistic Aharonov-Bohm rings including a random distribution of impurities and analyze the LDOS-$ΔG$ correspondence by means of exact numerical simulations, when localized states or semi-classical orbits characterize the wavefunction of the system.

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M. G. Pala, B. Hackens, F. Martins, H. Sellier, V. Bayot, S. Huant, T. Ouisse. 2007-11-21. Local Density of States in Mesoscopic Samples from Scanning Gate Microscopy. https://doi.org/10.1103/physrevb.77.125310

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