Photoinduced phase transitions by time-resolved far-infrared spectroscopy in V₂O₃

Using time-resolved far-infrared spectroscopy, we observe multiple routes for photoinduced phase transitions in V₂O₃. This includes (i)a photothermal antiferromagnetic to paramagnetic transition and (ii)an incipient strain-generated paramagnetic metal to paramagnetic insulator transition, which manifests as coherent oscillations in the far-infrared conductivity. The ∼100ps conductivity oscillation results from coherent acoustic phonon modulation of the bandwidth W. Our results indicate that poor metals are particularly amenable to coherent strain control of their electronic properties.