To begin to understand the field of plasmonics, picture the rich colors of stained glass windows in Gothic cathedrals; or, the pixelation of a digital photo on a laptop screen. In some way, shape or form these are plasmons on display. Basically, plasmons are traveling waves of rippling electrons that can be excited in plasmas, metals or semiconductors. They lie at the heart of plasmonics. In such systems, plasmons bunch up and spread out as a group, enhancing and manipulating electromagnetic energy and concentrating optical energy beyond the diffraction limit of light. But much of this energy in common materials is quickly lost, or dissipated, as heat. And, while plasmons have found commercial applications in chemical sensors (e.g., common drug-store pregnancy tests), they have not been applied more widely or ambitiously because of high dissipation, which has frustrated scientists—until now.
The race is on between new antibiotics and drug-resistant bacteria—and scientists are challenged to keep up. By 2050, according to a Wellcome Trust study, deaths from deadly infections will be more common than cancer deaths. Scientists report that currently antimicrobial resistance causes 23,000 deaths annually in the U.S.; 700,000 deaths worldwide. Better methods to treat bacterial infections are urgently needed. So researchers, including a University of California San Diego professor, are gaining ground by demonstrating the first example of an effective gene therapy for deadly bacterial infections.
The headaches of heavy traffic may be universal, but University of California San Diego’s Ruth Williams works to ease the pain. The Department of Mathematics professor analyzes traffic congestion within the field of stochastic networks. This area of math describes real-world systems running at near-maximum capacity. It applies to things like the Internet when congested, assembly line glitches, customer service queues and freeways at rush hour. For this work, and for her many contributions to probability theory and collaborative research, Williams has been selected as a Corresponding Member of the Australian Academy of Science. The U.K.’s Professor Richard Ellis joins her as a new academy member.
As if taken from a Star Wars or Star Trek movie script, the term “exciton” (pronounced ˈek-sə-tän) comes from condensed matter physics. Excitons are bound states of electrons and electron holes attracted to each other by electrostatic force. They can be created both by light and transformed into light. Electrically neutral, these quasiparticles exist in systems like insulators and semiconductors, but University of California San Diego physicists have established a way that may bring them into future cell phones and laptops.
University of California San Diego’s Wei Xiong studies the science of “in between.” Specifically, the physical chemist studies mixed states of light and matter in order to better understand how the two forms of energy interact and communicate. Xiong does this by mixing light and matter to create hybrid quantum combinations whose properties he and his team measure and analyze. Recent research by Xiong; Bo Xiang, a Ph.D. candidate in his group; and postdoctoral scholar Raphael Ribeiro, from the Joel Yuen-Zhou Group, was published by Proceedings of the National Academy of Sciences (PNAS) in an article titled, “Two-dimensional infrared (2D IR) spectroscopy of vibrational polaritons.”
Exploring space beyond our solar system, UC San Diego Professor of Physics Adam Burgasser collaborated with an international team of astronomers, led by Nikolay Nikolov from the University of Exeter, to discover that the atmosphere of an exoplanet named WASP-96b, a so-called “hot Saturn,” is cloud-free. Their research is now published in the scientific journal Nature in an article titled, “An absolute sodium abundance for a cloud-free ‘hot Saturn’ exoplanet.”
