We study the relationship between the local density of states (LDOS) and the conductance variation Delta G 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 Delta G is proportional to the Hilbert transform of the LDOS and hence a generalized Kramers-Kronig relation holds between LDOS and Delta G. 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-Delta G correspondence by means of exact numerical simulations, when localized states or semiclassical orbits characterize the wave function of the system.
Local density of states in mesoscopic samples from scanning gate microscopy
Pala M;
2008-01-01
Abstract
We study the relationship between the local density of states (LDOS) and the conductance variation Delta G 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 Delta G is proportional to the Hilbert transform of the LDOS and hence a generalized Kramers-Kronig relation holds between LDOS and Delta G. 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-Delta G correspondence by means of exact numerical simulations, when localized states or semiclassical orbits characterize the wave function of the system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
