Electron correlations in a quantum dot with Bychkov-Rashba coupling

We report on a theoretical approach developed to investigate the influence of the Bychkov-Rashba interaction on a few interacting electrons confined in a quantum dot. We note that the spin-orbit coupling profoundly influences the energy spectrum of interacting electrons in a quantum dot. Interelectron interaction causes level crossings in the ground state and a jump in magnetization. As the coupling strength is increased, that jump is shifted to lower magnetic fields. Low-field magnetization will therefore provide a direct probe of the spin-orbit coupling strength in a quantum dot.

Figure 1

Energy spectrum of a two-electron InAs quantum dot versus the applied magnetic field for different values of the Bychkov-Rashba interaction parameter $\alpha$ (meV nm). For clarity, at each value of the magnetic field and for a given total angular momentum, only the lowest energy is plotted. The Zeeman energy is also included.

Figure 2

The same as in Fig. 1, but for the InSb quantum dot system.

Figure 3

Magnetization in the ground state for various values of the SO coupling strength and for the two QD systems.