SCL member Milos Radonjic held a seminar talk entitled "Wigner-Mott scaling of transport near the two-dimensional metal-insulator transition"

Abstract of the talk:

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 ρ_max increases. Here we show that in this regime, the entire family of resistivity curves displays a characteristic scaling behavior ρ(T )/ρ_max ≈ F(T / T_max), while the ρ_max and T_max ∼ 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.