Unique macroscopic phenomena, such as high-temperature superconductivity and colossal magnetoresistance, emerge in quantum materials due to the interplay between their electronic, magnetic, and structural degrees of freedom. This interplay also results in phases that can be tuned by manipulating their atomic structure and symmetry. In this talk, I will discuss two complementary “non-equilibrium” pathways for inducing and influencing novel properties in quantum materials: atomic layer heterostructuring and optical lattice control.
First, I will describe the use of molecular beam epitaxy to shape electronic structure and transport through atomically-precise interfacial engineering. As an example, this method is applied to design the conductivity and orbital configuration of rare-earth nickelates. Second, I will show that resonantly driving optical phonons with terahertz-frequency pulses provides a route to control of electronic and magnetic behavior on ultrafast time scales. This approach is illustrated by a recent experiment, in which the antiferromagnet CoF2 is optically driven into a ferromagnetic phase with a 100-fold larger magnetization than statically achievable.
Using these forms of control in tandem enables the rational design of non-equilibrium behavior, providing a unique path to explore and exploit the physics of quantum materials.
