Transport and optical properties across the Mott transition (Through Skype)

Strong Coulomb repulsion between electrons in a crystal lattice can
cause localization of electrons and results in a metal-to-insulator
transition. Such a transition is known as the Mott transition and the
insulating phase is called the Mott insulator.

After the discovery of cuprate superconductors in 1986, physics around
the Mott transition has received immense attention as they originate
from a doped Mott insulator.  We have attempted to capture some of the
essential features of the transport and optical properties in the
'normal' phase of the cuprate phase diagram, using the dynamical
mean-field theory (DMFT) applied to the particle-hole asymmetric
single-band Hubbard model. We have employed the local moment approach
(LMA) to solve the impurity problem in the context of DMFT. I shall
discuss our results and physical implication of our approach and make
comparison to recent experiments on several cuprate compounds.

In the second part of my talk, I shall discuss another interesting
phenomenon, namely the occurrence of steps or avalanches in the
resistance hysteresis in the Mott transition systems. We formulate a
resistor-network based model mapped from a random-field Ising model
(RFIM) in order to investigate the stochastic behavior of the
resistance avalanches. Our work has been motivated by a recent
experiment on the vanadium dioxide material, a prototype that
encounters Mott transition due to change in temperature.