The innovation engine for new materials

Alec Cao

Alec Cao




University of California, Santa Barbara


Kurt Fujiwara
Kevin Singh
Misha Lipatov

Faculty Sponsor(s): 

David Weld

Faculty Sponsor's Department(s): 


Project Title: 

Driving Ultracold Lithium in an Optical Lattice

Project Description: 

Ultracold quantum emulation is a powerful tool for probing condensed matter systems. In this field, low temperature, neutral atoms in an optical lattice made of lasers are analogous to valence electrons in a crystal lattice. Two important features of this are that optical lattice atoms possess a band structure and optical lattice potential energy can be manipulated with laser modulation. For these reasons, quantum emulation lends itself to studying driven lattices, which are lattices under the influence of some external drive, such as an oscillating electric field, that alters its potential energy over time. Specifically, we are interested in periodic drives at resonant frequencies that lead to what can be thought of as a stitching together of different bands, and this stitching procedure could enable engineering of electronic properties in materials. Understanding lattice dynamics during resonant drives could hold key insights into ultrafast energy transport and nonequilibrium phenomena in solids. Quantum emulation enables us to investigate these crucial solid-state systems using ultracold gases of lithium. After loading the gas into an optical lattice and modulating for variable amounts of time, we image the atoms to observe the driven lattice dynamics. So far, we have successfully engineered rapid, long-range transport of the atoms across the lattice by addressing the ground to second excited band resonance. We are currently attempting to simultaneously drive our optical lattice at multiple resonant frequencies and realize more complex band structures that should arise from multiple stitching procedures.