Vanadium dioxide, an archetypal correlated-electron material, undergoes an insulator-metal transition near room temperature that exhibits electron-correlation-driven and structurally-driven physics. Using ultrafast optical spectroscopy and x-ray scattering we show that these processes can be disentangled in the time domain. Specifically, following intense sub-picosecond electric-field excitation, a partial collapse of the insulating gap occurs within the first ps. Subsequently, this electronic reconfiguration initiates a change in lattice symmetry taking place on a slower timescale. We identify the kinetic energy increase of electrons tunneling in the strong electric field as the driving force, illustrating a novel method to control electronic interactions in correlated materials on an ultrafast timescale.
@article{arxiv.1601.07490,
title = {Ultrafast THz Field Control of Electronic and Structural Interactions in Vanadium Dioxide},
author = {A. X. Gray and M. C. Hoffmann and J. Jeong and N. P. Aetukuri and D. Zhu and H. Y. Hwang and N. C. Brandt and H. Wen and A. J. Sternbach and S. Bonetti and A. H. Reid and R. Kukreja and C. Graves and T. Wang and P. Granitzka and Z. Chen and D. J. Higley and T. Chase and E. Jal and E. Abreu and M. K. Liu and T. -C. Weng and D. Sokaras and D. Nordlund and M. Chollet and H. Lemke and J. Glownia and M. Trigo and Y. Zhu and H. Ohldag and J. W. Freeland and M. G. Samant and J. Berakdar and R. D. Averitt and K. A. Nelson and S. S. P. Parkin and H. A. Dürr},
journal= {arXiv preprint arXiv:1601.07490},
year = {2018}
}