Few-electron liquid and solid phases in artificial molecules at high magnetic field

TL;DR

This paper investigates how high magnetic fields influence the phase transitions of electrons in artificial molecules formed by coupled quantum dots, revealing conditions for electron localization and Wigner crystal formation.

Contribution

It provides a detailed phase diagram of Wigner molecules, emphasizing the impact of tunneling on ground state stability using configuration interaction methods.

Findings

Identification of conditions for electron localization

Role of tunneling in stabilizing phases

Analysis of phase transitions under magnetic fields

Abstract

Coupled semiconductor quantum dots form artificial molecules where relevant energy scales controlling the interacting ground state can be easily tuned. By applying an external magnetic field it is possible to drive the system from a weak to a strong correlation regime where eventually electrons localize in space in an ordered manner reminiscent of the two-dimensional Wigner crystal. We explore the phase diagram of such "Wigner molecules" analyzing the angular correlation function obtained by the Configuration Interaction solution of the full interacting Hamiltonian. Focus is on the role of tunneling in stabilizing different ground states.