Methods for distinguishing Mott transitions from Anderson transitions

Metal-insulator transitions (MITs) (resistive switching) is an important research area. The underlying mechanisms are complex and have not been completely understood. Two or more different transitions can be induced simultaneously. Thus, to better understand the mechanisms of MITs for a specific material, it is necessary to design criteria for differentiating between transition mechanisms. Here, we studied resistive switching in Mott and Anderson insulators. These insulators (exhibiting Mott and Anderson resistive switching) were distinguished based on their properties. In Anderson insulators, electron states are localised at the Fermi level without a band gap, and resistivity is given by In rho = AT(-1/4) within a certain range of temperatures. However, in Mott insulators, the Fermi level features a band gap, and ln rho does not linearly depend on T-1/4 . Therefore, optical conductivity, which can predict materials' band gaps and resistivity-temperature characteristics, can be used for distinguishing between Mott and Anderson types of resistive switching.