From sub-atomic to astronomical scales, we are working on the frontiers of science. A tradition of bridging boundaries has allowed us to probe fundamental questions at the intersections different branches of science and mathematics and to create new fields of study. Because mathematics and the physical sciences are fundamental to many pursuits, including engineering, medicine and biology, we contribute to the education of most undergraduate students at UC San Diego.
Light becomes trapped as it orbits within tiny granules of a crystalline material that has increasingly intrigued physicists, a team led by physics professor Michael Fogler has found. Hexagonal boron nitride, stacked layers of boron and nitrogen atoms arranged in a hexagonal lattice, has recently been found to bend electromagnetic energy in unusual and potentially useful ways. Last year Fogler and colleagues demonstrated that light could be stored within nanoscale granules of hexagonal boron nitride. Now Fogler's research group has published a new paper in the journal Nano Letters that elaborates how this trapped light behaves inside the granules.
The particles of light, called phonon polaritons, disobey standard laws of reflection as they bounce through the granules, but their movement isn't random. Polariton rays propagate along paths at fixed angles with respect to the atomic structure of the material, Folger's team reports. That can lead to interesting resonances. “The trajectories of the trapped polariton rays are very convoluted in most instances,” Fogler said. “However, at certain ‘magic’ frequencies they can become simple closed orbits. Learn more.
Scientists have designed nanoparticles that release drugs in the presence of a class of proteins that enable cancers to metastasize. A peptide coating around nanospheres of paclitaxel shields the anti-cancer drug as it travels through the circulatory system. Enzymes secreted by cancers to enable metastasis slice open the shell. The targeted delivery allowed them to safely give mice 16 times the maximum tolerated dose of the clinical formulation of paclitaxel and halted the growth of cancerous tumors. Learn more.
There may be many fewer galaxies in the farthest reaches of the universe than previous estimates predicted, according to simulations run by physics professor Michael Norman's group working with colleagues at Michigan State University. Using the National Science Foundation’s Blue Waters supercomputer, they determined that the increase in number of faint, distant galaxies was flat rather than exponential, as previous studies had suggested. Learn more.
The National Science Foundation has awarded a $5 million grant to support the Simons Array, a new system of three powerful telescopes designed to study the origins of the universe. Cosmologists will use the array of three telescopes to search for the signature of cosmic inflation—the rapid expansion of the early universe after the Big Bang—by making high-fidelity maps of polarization in the cosmic microwave background. The project's search for these twists in the CMB was recently profiled in the Proceedings of the National Academy of Sciences.
Physicists have found a way to control the length and strength of waves of atomic motion that have promising potential uses such as fine-scale imaging and the transmission of information within tight spaces.
The researchers measured waves called polaritons that can emerge when light interacts with matter. By combining two materials, they produced hybrid polaritons that propagate throughout many layers of a crystalline material and can be controlled with a simple electrical gate. Learn more.
UC San Diego’s Department of Chemistry and Biochemistry ranked second in the nation in a new survey of professorships held by underrepresented minorities. Learn more.