Effective mass of quasiparticles in a Wigner liquid

The exchange interaction and effective mass of fermionic excitation in a low-density ($r_S\gg1$). system of two-dimensional electrons are estimated from simple considerations. For the ratio of effective (renormalized due to interaction) to band mass, the dependence $m^*/m =(A/\sqrt{r_S}) \exp(\alpha\sqrt{r_S})$, is obtained, where $A$ and $\alpha$ are constants on the order of unity. The effective $g$ factor is independent of $r_S$ and is larger than its bare value in the two-valley case (silicon). Comparison with experimental data shows a qualitative agreement with silicon.