We determine the spin susceptibility $\chi$ in the weak interaction regime of a tunable, high quality, two-dimensional electron system in a $\mathrm{Ga}\mathrm{As}∕\mathrm{Al}\mathrm{Ga}\mathrm{As}$ heterostructure. The band structure effects, modifying mass and $g$-factor, are carefully taken into accounts since they become appreciable for the large electron densities of the weak interaction regime. When properly normalized, $\chi$ decreases monotonically from 3 to 1.1 with increasing density over our experimental range from 0.1 to $4\times {10}^{11}{\mathrm{cm}}^{-2}$. In the high density limit, $\chi$ tends correctly towards $\chi \to 1$ and compare well with recent theory.

• Received 13 April 2005

DOI:https://doi.org/10.1103/PhysRevB.73.045334