Small-Signal Circuit Elements of MIS-Type Nanostructures
Starting from a mean field calculation for the static capacitance of a MIS-nanostructure with a near back gate [P.N. Racec, E. R. Racec and U. Wulf, Phys. Rev. B 65, 193314, (2002)] we develop an approach to determine the equivalent small-signal circuit. The analyzed system has an open character, taken into account in the Landauer-Büttiker formalism. The Coulomb interaction is treated in Hartree approximation. Consistent with our static calculations we determine the charge-charge correlation function in the random phase approximation to find the ac-admittances. The small-signal circuit consists of a voltage-dependent capacitance and a resistance in series. Beyond a characteristic frequency c ν they become frequency dependent. The characteristic frequency is given by the life time of specific resonance which develops in the system.
Chunli BAI, Sishen XIE, Xing ZHU
P.N. Racec and U. Wulf, "Small-Signal Circuit Elements of MIS-Type Nanostructures", Solid State Phenomena, Vols. 121-123, pp. 549-552, 2007