Discovery of Light-induced Metastable Martensitic Anomaly Controlled by Single-Cycle Terahertz Pulses

Academic Article

Abstract

  • We report on an ultrafast photoinduced phase transition with a strikingly long-lived Martensitic anomaly driven by above-threshold single-cycle terahertz (THz) pulses in Nb$_3$Sn. A non-thermal, THz-induced depletion of low frequency conductivity indicates increased gap splitting of high energy $\Gamma_{12}$ bands by removal of their degeneracies which enhances the Martensitic phase. In contrast, optical pumping leads to a $\Gamma_{12}$ gap melting. Such light-induced non-equilibrium Martensitic instability persists up to a critical temperature $\sim$100 K, i.e., more than twice the equilibrium temperature, and can be stabilized beyond technologically-relevant, nanosecond timescales. Together with first-principle simulations, we identify a compelling THz tuning of structural fluctuations via E$_u$ phonons to achieve a non-equilibrium ordering at high temperatures far exceeding those for equilibrium states.
  • Authors

    Keywords

  • cond-mat.str-el, cond-mat.str-el, cond-mat.mtrl-sci, cond-mat.supr-con
  • Author List

  • Yang X; Song B; Vaswani C; Luo L; Sundahl C; Mootz M; Kang J-H; Yao Y; Ho K-M; Perakis IE