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Compressibility, capacitance and ground state energy fluctuations in a weakly interacting quantum dot

R. Berkovits·B. L. Altshuler
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Abstract

We study the effect of electron-electron (e-e) interactions on compressibility, capacitance and inverse compressibility of electrons in a quantum dot or a small metallic grain. The calculation is performed in the random-phase approximation. As expected, the ensemble-averaged compressibility and capacitance decreases as a function of the interaction strength, while the mean inverse compressibility increases. Fluctuations of the compressibility are found to be strongly suppressed by the e-e interactions. Fluctuations of the capacitance and inverse compressibility also turn out to be much smaller than their averages. The analytical calculations are compared with the results of a numerical calculation for the inverse compressibility of a disordered tight-binding model. Excellent agreement for weak interaction values is found. Implications for the interpretation of current experimental data are discussed.

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R. Berkovits, B. L. Altshuler. 1996-10-30. Compressibility, capacitance and ground state energy fluctuations in a weakly interacting quantum dot. https://doi.org/10.1103/physrevb.55.5297

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