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 �max increases. Here we show that, in this regime, the entire family of resistivity curves displays a characteristic scaling behavior �(T )/�max � F(T/Tmax), while the �max and Tmax � T � assume a powerlaw dependence on the quasi-particle 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.\u