Spin splitting of the electron ground states of InAs quantum dots

Here, we present results on the spin splitting of electrons in the ground state of InAs self-assembled quantum dots (QDs). The spin splitting is assessed by capacitance spectroscopy, which allows direct measurement of the electronic g-factor modulus. By applying the magnetic field parallel to the [001], [110], and [1 (1) over bar0] crystallographic directions, we found that for magnetic fields below 5 T the g factor depends on the orientation, reflecting the QD anisotropy. For higher fields, the g factor does not exhibit the same degree of anisotropy, indicating a compression of the wave function inside the QD along the [001] direction, and consequently, a dependence on the magnitude of the applied field. (C) 2002 American Institute of Physics.