2017/06/02 by F. Giorgianni, Flavio Giorgianni, Giorgianni, Flavio +14
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Gas Sensing Nanomaterials and Sensors #Photorefractive and Nonlinear Optics #Strongly Correlated Electrons (cond-mat.str-el) #Transition Metal Oxide Nanomaterials #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1706.00616
One of the coauthor, M. Shalaby, asked to remove the paper
openalex publication_date 2017/06/02 · openalex created_date 2017/06/09 · arxiv created 2017/09/01 · arxiv updated 2017/09/04 · openalex updated_date 2026/07/28
In vanadium dioxide, the interplay between coherent lattice transformation and electronic correlation drives an insulator-to-metal transition (IMT). This phase commutation can be triggered by temperature, pressure, doping or deposition of optical energy. Here we demonstrate that an atomically-strong terahertz electric field initiates a metastable ultrafast IMT in vanadium dioxide without a concomitant lattice transformation. The free-space terahertz field acts as off-resonant excitation with photon energy below the lattice phonons and the interband transitions. Differently from optical and infrared excitation, terahertz interaction leads to a full IMT by interband Zener tunneling with a negligible entropy deposition. In previous experiments the temporal dynamics of IMT in VO2 could be only indirectly inferred. We disentangle the electronic and lattice contributions to the IMT on a sub-picosecond timescale. Near the critical temperature the IMT becomes dissipative and the terahertz field concludes the lattice-assisted metallic nucleation initiated by heating. The method of strong-field induced phase transition presented here is applicable to a wide class of strongly correlated systems and will enable the discovery of novel metastable phases.