Overcoming the thermal regime for the electric-field driven Mott transition in V2O3
The complex interplay of electronic, spin and lattice degrees of freedom in strongly correlated Mott–Hubbard materials leads to exotic physical phenomena as Insulator-to-Metal transition (IMT), colossal magnetoresistance, giant thermochromic effects, and High-Tc superconductivity. Although, IMT can be triggered by external perturbations and parameters like temperature, pressure, chemical doping and light irradiation, the role of different degrees of freedom in establishing the IMT and their time-scale cannot be easily disentangled.
Recently a collaboration among the Paul Scherrer Institute in Switzerland (Dr. Flavio Giorgianni) and the TERALAB laboratory of the Department of Physics (Prof. Stefano Lupi), has shown the emergence of a purely-electronic ultrafast IMT in the Mott-Hubbard prototype Vanadium Sequioxide (V2O3) material https://www.nature.com/articles/s41467-019-09137-6.
This ultrafast IMT is driven by a highly-intense terahertz (THz) pulse with an associated electric field of multi-MV/cm oscillating on the fs scale which generates conductive states by quantum tunneling of valence electrons across the band gap. As a general perspective, high intensity ultrashort terahertz radiation is the candidate ultrafast technique for controlling magnetic, electronic and vibrational excitations in quantum matter.
Reference
Nature Communications
Authors: Flavio Giorgianni and Stefano Lupi