Transport of GaAs two-dimensional holes in strong Coulomb interaction regime

We report experimental findings on the 2D holes in a GaAs/AlGaAs heterojunction insulated-gate field-effect transistor in the strong interaction regime ($E_{ee}>>E_ {F},kT$) with the carrier densities (p) varying from $7\times10^ {9}$ $cm^{-2} $ to $7\times10^{8}$ $cm^{-2}$. Though the temperature dependence of the resistivity ($\rho$) resembles that observed in typical 2D Metal-to-Insulator Transition (MIT), there are two things strikingly different. First, for each density, a kink/dip appears in the $T$-dependence of the conductivity ($\sigma$) around a characteristic temperature which we call $T_{c}$. In the $T_{c}$-$p$ relation, there is a sudden change at a characteristic density which is the same as the critical density $p_{c}$ where the apparent MIT is observed. The linear $T_{c}$-$p$ at high densities suggests that $T_{c}$s for $p>p_{c}$ correspond to the Fermi temperature $T_{F}$s. However, $T_{c}$ shows little $p$- dependence at $pT_{c}$ and a power-law part for $T