Ultrafast Terahertz and Optical Spectroscopy under Synergetic Extreme Conditions

Elucidating and manipulating emergent phases in complex materials requires direct access to their low-energy collective modes. Terahertz (THz) time-domain and ultrafast optical spectroscopies have emerged as indispensable experimental tools, enabling the probing of intrinsic electrodynamics and the coherent control of non-equilibrium states. At the Synergetic Extreme Condition User Facility (SECUF), we have developed a suite of intense ultrashort light sources covering the near-infrared, mid-infrared, and THz spectral ranges. By integrating these strong-field pulses with extreme sample environments, such as low temperatures, strong magnetic fields, and high pressures, we have established several state-of-the-art spectroscopy platforms. In this article, we outline the technical specifications of each setup and highlight representative user experiments. The presented results underscore the exceptional capability of the THz experimental unit (A4-2) to explore ultrafast dynamics across a multi-parameter thermodynamic phase space.