Fluctuations of Conductance Peak Spacings in the Coulomb Blockade Regime: Role of Electron-Electron Interaction

TL;DR

This paper investigates how electron-electron interactions and eigenfunction fluctuations influence the statistical distribution of Coulomb blockade peak spacings in disordered quantum dots, revealing enhanced fluctuations and spin-related structures.

Contribution

It demonstrates the combined effect of electron-electron interactions and eigenfunction fluctuations on peak spacing statistics, including the impact of spin degrees of freedom.

Findings

Interaction and eigenfunction fluctuations increase peak spacing variability.

Weak interactions produce an odd-even peak spacing pattern.

Strong interactions eliminate the odd-even structure.

Abstract

We study influence of electron-electron interaction on statistics of Coulomb blockade peak spacings in disordered quantum dots. It is shown that the interaction combined with fluctuations of eigenfunctions of the Fermi sea, enhances the peak spacing fluctuations, in accordance with recent experiments. In addition, account of the spin degrees of freedom leads to a pronounced odd-even structure for weak interaction ($e^2/\epsilon \ll v_F$); in the opposite case ($e^2/\epsilon \gtrsim v_F$) this structure is washed out.