Engineering High-Temperature and Magnetic Phases in Complex Oxides with THz Light

Complex oxides exhibit a host of competing electronic, magnetic, and structural interactions, which leads to emergent phases with enormous technological potential, such as superconductivity and multiferroicity. The low-temperature scales associated with their quantum behavior, however,often hinders their practical application. In this talk, I will describe a methodology to engineer the crystal structure of materials dynamically with ultrashort THz-frequency light pulses. By driving the ions in the crystal lattice to large amplitudes, we can exploit nonlinearities to tune electronic and magnetic interactions, break symmetries, and unlock new phases at elevated temperatures. I will highlight some recent experiments demonstrating the ability to optically control, enhance, and induce magnetism and ferroelectricity in complex oxides. In particular, I will show how ferromagnetism can be stabilized at temperatures more than three times the equilibrium ordering temperature by selectively driving optical phonons. In addition, I will touch upon our current efforts of integrating atomic layer materials synthesis to enable the rational design of non-equilibrium functionalities for next-generation quantum and ultrafast technologies.

Host: Aaron Sternbach