Wigner-Mott scaling of transport near the two-dimensional metal-insulator transition

Electron-electron scattering usually dominates the transport in strongly correlated materials. It typically leads to pronounced resistivity maxima in the incoherent regime around the coherence temperature T*, reflecting the tendency of carriers to undergo Mott localization following the demise of the Fermi liquid. This behavior is best pronounced in the vicinity of interaction-driven (Mott-like) metal-insulator transitions, where the T* decreases, while the resistivity maximum rho(max) increases. Here we show that in this regime, the entire family of resistivity curves displays a characteristic scaling behavior rho(T)/rho(max) approximate to F(T/T-max), while the rho(max) and T-max similar to T* assume a power-law dependence on the quasiparticle effective mass m*. Remarkably, precisely such trends are found from an appropriate scaling analysis of experimental data obtained from diluted two-dimensional electron gases in zero magnetic fields. Our analysis provides strong evidence that inelastic electron-electron scattering-and not disorder effects-dominates finite-temperature transport in these systems, validating the Wigner-Mott picture of the two-dimensional metal-insulator transition.