Magnetic-field-induced binding of few-electron systems in shallow quantum dots

TL;DR

This study investigates how external magnetic fields enable binding of few-electron systems in shallow quantum dots, revealing a non-smooth dependence on magnetic field strength and convergence to classical values at high fields.

Contribution

The paper demonstrates that magnetic fields induce binding in shallow quantum dots and characterizes the non-smooth dependence of binding thresholds on magnetic field strength.

Findings

Binding occurs only under strong magnetic fields in shallow cavities.

Critical cavity depth decreases non-smoothly with increasing magnetic field.

Binding energies approach classical values at high magnetic fields.

Abstract

Binding of few-electron systems in two-dimensional potential cavities in the presence of an external magnetic field is studied with the exact diagonalization approach. We demonstrate that for shallow cavities the few-electron system becomes bound only under the application of a strong magnetic field. The critical value of the depth of the cavity allowing the formation of a bound state decreases with magnetic field in a non-smooth fashion, due to the increasing angular momentum of the first bound state. In the high magnetic field limit the binding energies and the critical values for the depth of the potential cavity allowing the formation of a bound system tend to the classical values.