Boerge Hemmerling, an assistant professor of physics and astronomy at the University of California, Riverside, has received a five-year grant of nearly $1 million from the National Science Foundation to study nonlinear optical properties and novel quantum phases of polar molecules in optical lattices. Nonlinear optical properties of molecular crystals (second-harmonic generation of light with molecules trapped in optical lattice). Courtesy of the Hemmerling lab, UC Riverside. Hemmerling is the grant’s principal investigator. Shan-Wen Tsai, an associate professor of physics and astronomy, and Christopher Bardeen, a professor of chemistry, are co-principal investigators. The trio will research the use of optical trapping methods — techniques that trap particles using light — to prepare molecular assemblies where parameters such as molecular spacing, degree of order, and orientation can be tuned by external fields. “Controlling complex quantum systems, such as molecules, is one of the next big steps in developing novel quantum technologies,” Hemmerling said. “To develop novel molecular materials, we need to be able to synthesize their constituents and assemble them under carefully controlled conditions. The optical trapping methods we plan to use will allow us to study the basic properties of solid-state materials in a cheaper, more flexible way.” In their experiments, the researchers will trap molecules in optical lattices by mimicking the molecular arrangement and properties of a solid crystal, and orienting these molecules using external electric fields. “The observation of novel quantum phenomena in our optical lattice crystals will help guide the design of future molecular materials such as nanocrystal assemblies or metal-organic frameworks, that could exhibit novel properties,” Hemmerling said.