Exchange interaction effects in the thermodynamic properties of quantum dots

TL;DR

This paper investigates how exchange interactions influence the thermodynamic properties of quantum dots, revealing an exchange-induced phase transition and effects on magnetic oscillations, with implications for nanoscale electronic systems.

Contribution

It provides a detailed analysis of exchange effects on specific heat and magnetic oscillations in quantum dots using self-consistent Hartree-Fock approximation, highlighting a novel exchange-induced phase transition.

Findings

Exchange-induced phase transition observed.

Transition temperature inversely proportional to system size.

Exchange contribution dominates in intermediate interaction regime.

Abstract

We study electron-electron interaction effects in the thermodynamic properties of quantum-dot systems. We obtain the direct and exchange contributions to the specific heat C_v in the self-consistent Hartree-Fock approximation at finite temperatures. An exchange-induced phase transition is observed and the transition temperature is shown to be inversely proportional to the size of the system. The exchange contribution to C_v dominates over the direct and kinetic contributions in the intermediate regime of interaction strength (r_s ~ 1). Furthermore, the electron-electron interaction modifies both the amplitude and the period of magnetic field induced oscillations in C_v.