QSMI Seminar: Stabilizing high-temperature ordered phases in correlated materials with light
Correlated quantum materials host competing charge, spin, orbital, and lattice interactions, giving rise to complex phase diagrams and strongly fluctuating quantum states. While providing tunability, this phase competition can suppress long-range order, such that desirable properties are pushed to low temperatures, or in some cases, may not form at all in thermal equilibrium. In this talk, I will describe a methodology to stabilize electronic and magnetic phases in quantum materials at high temperatures by manipulating the crystal lattice dynamically with ultrashort light pulses. The approach is based on using tailored THz-frequency excitation to drive large amplitude atomic motions, effectively providing a knob to tune interactions, break symmetries, and unlock new non-equilibrium states. I will describe experiments demonstrating light-driven ferromagnetism that can persist at temperatures more than three times larger than the equilibrium Tc. In addition, I will highlight our ongoing efforts to realize room-temperature multiferroicity by integrating atomic scale synthesis with targeted optical excitation. This work sets the stage for the development of a new paradigm for “non-equilibrium materials design” for next-generation quantum and ultrafast technologies.
Speakers
Ankit Disa earned his B.S. in from Cornell University in 2010 and his Ph.D. from Yale University in 2016. His doctoral work focused on manipulating electronic and magnetic properties of complex oxides through the synthesis of atomically precise heterostructures. He then joined the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany as a postdoctoral scientist, where he developed novel methods to control functional properties on ultrafast time scales using THz light. In 2017, he was awarded the Alexander von Humboldt Research Fellowship. In 2019, he became a fellow of the Max Planck-NYC Center for Non-equilibrium Quantum Phenomena based at Columbia University. He returned to Cornell in July 2022 to join the faculty in Applied and Engineering Physics as an Assistant Professor where he leads the Disa Lab focused on understanding and engineering non-equilibrium properties in quantum materials through a combination of atomic scale synthesis and ultrafast optical techniques.