Quantum Materials and Devices Seminars

Non-equilibrium control of magnetic order by engineering crystal structures with light

Ankit Disa

Apr 27, 2022
1:30 pm to 2:30 pm | Remote

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Quantum materials exhibit unique macroscopic phenomena with enormous technological potential, ranging from high-temperature superconductivity to topologically protected transport. Due to the strongly intertwined nature of electrons and the crystal lattice in these materials, manipulating the atomic structure allows one to tune interactions and create novel electronic and magnetic phases. In this talk, I will describe how light can be used to engineer structural distortions on ultrafast time scales, providing a powerful pathway to realize non-equilibrium states of matter, often with functionalities not accessible otherwise. I will focus on two recent experiments illustrating the application of this approach to dynamically control, enhance, and stabilize magnetism in quantum materials. The first concerns the simple antiferromagnet CoF2, in which we optically drive ferrimagnetic phase transition, whose induced magnetization is 100-fold larger than the equilibrium limit. The second demonstrates that magnetic order in a correlated ferromagnet with strong spin-orbital fluctuations (YTiO3) can be transiently enhanced and stabilized at a temperature well in excess of the equilibrium Tc [5]. These examples are enabled by selectively exploiting phonon nonlinearities, providing a basis for the rational design of non-equilibrium functionalities. Integrated with targeted materials synthesis, such control promises to unlock new physical phenomena and enable next-generation quantum and ultrafast technologies.


Emily Haderer