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 $T^{\ast }$, 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 $T^{\ast }$ 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 $\rho (T)\mathrm{/}{\rho }_{max}\approx F(T\mathrm{/}{T}_{max}),$ while the ${\rho }_{max}$ and $T_{max}\sim T^{\ast }$ assume a powerlaw dependence on the quasi-particle effective mass $m^{\ast }$. 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.