Fermi-liquid behavior of the low-density 2D hole gas in a GaAs/AlGaAs heterostructure at large values of rs

We examine the validity of the Fermi-liquid description of the dilute 2D hole gas in the crossover from metallic-to-insulating behavior of p(T). It has been established that, at r(s) as large as 29, negative magnetoresistance does exist and is well described by weak localization theory. The dephasing time, extracted from the magnetoresistance, is dominated by the T-2 term due to hole-hole scattering in the clean limit. The effect of hole-hole interactions, however, is suppressed when compared with the theory derived for small r(s),.