Abstract by Lauren Rawlings
Chemistry and Biochemistry
Terahertz Waveform Considerations for Nonlinearly Driving Lattice Vibrations
Using terahertz (THz) light to push atoms in crystals far from equilibrium positions can help us understand fundamental interactions in solids and motivate future technology development. We show that modifying the shape of the THz pulses can drive vibrations nonlinearly, indicating extreme excitation. To study if the nonlinear response was a result of the anharmonic potential energy surface or a 2-photon absorption mechanism, we performed single-pulse power dependent measurements, z-scan measurements, and simple 2D-THz measurements. There is some evidence that vibration anharmonicity is the main contributor, but additional measurements with stronger THz pulses would be needed for a more conclusive determination.