Wigner-Mott scaling of transport near the two-dimensional metal-insulator transition Milos Radonjic, D. Tanaskovic, V. Dobrosavljevic, K. Haule, G. Kotliar Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade Department of Physics and National High Magnetic Field Laboratory, Florida State University Department of Physics and Astronomy, Rutgers University Phys. Rev. B 85, (2012)

Outline 2D MIT in Si MOSFETs Coherent - Incoherent Experiments: resistivity in 2D diluted electron gases –Si MOSFET, GaAs hetero-structures Phenomenological scaling –Scaling Hypothesis –Critical behavior Scaling in 3D materials Scaling in the microscopic model of the interaction-driven metal- insulator transition

2D MIT in Si MOSFETs Early experiments and theory have not supported existence of metallic phase in Si MOSFETs

2D MIT in Si MOSFETs Scaling typical for systems with quantum critical point

Anderson or Mott-Wigner localization Early experiments and theory suggested insulator at lowest temperatures Anderson localization (non-interacting, weakly interactin particles), Abrahams et al. PRL (1979), Altshuler et al. PRL (1980) Wigner crystal (strong interaction), Ceperley et al. PRB (1989) Experiments on high mobility samples – diluted Existence of metallic region (up to )

Coherent or Incoherent transport At lowest temperatures elastic impurity scattering dominates Raising of temperature modify transport through Elastic scattering - modified screening, dephasing processes - (confirmed for good metals with weak disorder) Inelastic scattering – strong electron-electron interaction dominant in regime - (rare earth intermetallics, transition metal-oxides, organics Mott systems)

Resistivity in 2D diluted electron gases Typically found in strongly-correlated materials described by a single energy scale resistivity assumes additive form form systems with week and moderate disorder Inelastic Elastic

Scaling Hypothesis A single dominant transport mechanism Scaling holds in a very large range of concentrations

Critical behavior Landmark of strong correlations Power law

Scaling in 3D materials Heavy Fermion systemOrganic Mott system

Scaling near the Mott transition (DMFT) Radonjic et al, PRB 2012

This is more than coincidence! TheoryExperiment

Attention attracted by this work ROSS H. MCKENZIE BRISBANE, QUEENSLAND, AUSTRALIA