Development of a Gas Plasma-Based THz Time-Domain Spectrometer for the 25 T Split Florida Helix Magnet System

THz time-domain spectroscopy has been widely used to study two dimensional electron and hole gas systems.$^{\mathrm{1,2}}$ In order to extend the magnetic field range of these measurements we have developed a gas plasma-based THz time--domain spectrometer (TTDS) for use in the 25 T Florida Split Helix magnet system at the National High Magnetic Field Laboratory (NHMFL) at Florida State University. We have successfully quadrupled the bandwidth compared to traditional THz spectrometers (approx. 0.1-2.5 THz) based on non-linear crystals. We have recently performed the first high magnetic field TTDS measurements on a high mobility two dimensional electron gas sample. $^{\mathrm{1}}$Curtis, J. A.\textit{ et al.}, Physical Review B 2016, 93 (15), 155437. $^{\mathrm{2}}$Kamaraju, N.\textit{ et al.}, Applied Physics Letters 2015, 106 (3), 031902.