Showing papers on "Quantum capacitance published in 1999"
TL;DR: In this paper, the authors derived an exact expression for the electrochemical capacitance-voltage curve for a parallel plate system, which suggests a quantum scanning capacitance microscopy at the nanoscale.
Abstract: We analyze the nonlinear voltage dependence of electrochemical capacitance for nanoscale conductors. This voltage dependence is due to the finite density of states of the conductors. Within Hartree theory we derive an exact expression for the electrochemical capacitance–voltage curve for a parallel plate system. The result suggests a quantum scanning capacitance microscopy at the nanoscale: by inverting the capacitance–voltage expression one is able to deduce the local spectral function of the nanoscale conductor.
25 citations
TL;DR: In this paper, the authors demonstrate unipolar complementary circuits consisting of a pair of resonant tunneling transistors based on the gate control of 2D-2D interlayer tunneling, where a single transistor exhibiting a welldefined negative differential-resistance can be operated with either positive or negative transconductance.
Abstract: We demonstrate unipolar complementary circuits consisting of a pair of resonant tunneling transistors based on the gate control of 2D-2D interlayer tunneling, where a single transistor - in addition to exhibiting a welldefined negative-differential-resistance can be operated with either positive or negative transconductance Details of the device operation are analyzed in terms of the quantum capacitance effect and band-bending in a double quantum well structure, and show good agreement with experiment Application of resonant tunneling complementary logic is discussed by demonstrating complementary static random access memory using two devices connected in series
12 citations
TL;DR: In this paper, a simple Poisson-Schrodinger model was proposed to evaluate the quantum contribution in these cases, which can be seen as a quantum capacitance in series with the sum of capacitance around the dot.
Abstract: We discuss the limitations of the orthodox Coulomb-blockade theory when applied to silicon quantum dots in the nanometer range and we present a simple Poisson–Schrodinger model to evaluate the quantum contribution in these cases. This contribution can be seen as a quantum capacitance in series with the sum of capacitance around the dot. This simple model gives results similar to a more sophisticated one which includes Pauli principle, with a precision of the order of room-temperature thermal–energy kT . Finally we show that the simple model can be easily included in micro-electronic simulators and therefore can be very effective to predict new properties of future quantum devices. All the effects discussed in this paper are room-temperature effects.
4 citations
24 May 1999
TL;DR: In this paper, a reference resistor and a 10 nF capacitor are linked by means of a quadrature bridge based on a commercial two-phase generator, and the reference resistor can be measured with a standard uncertainty of less than 3 parts in 10/sup 5/ in the frequency range from 400 Hz to 5 kHz.
Abstract: A method is described which utilizes a 12906.4 /spl Omega/ resistor as a reference standard for capacitance calibrations. DC value of this resistor being obtained by comparing it against a quantum Hall effect device, its frequency dependence is measured by 1:1 comparison against a resistor having calculable frequency performance. Subsequently, the reference resistor and a 10 nF capacitor are linked by means of a quadrature bridge based on a commercial two-phase generator. The 10 nF capacitor, in turn, serves as a reference standard for calibration of capacitors of lower values by means of a four terminal-pair transformer bridge. By means of the quadrature bridge, capacitance can be measured with a standard uncertainty of less than 3 parts in 10/sup 5/ in the frequency range from 400 Hz to 5 kHz at the 10 nF level.