Experts in the News

Silicon has long reigned as the material of choice for the microchips that power everything in the digital age, from AI to military drones. Silicon chips have been bumping against the limits of miniaturization for years, dividing chip makers on whether Moore’s law, the longstanding assumption that transistors will steadily get smaller and computers more powerful, is already dead. But the global semiconductor industry is still under just as much pressure to produce ever more powerful chips, and keep up the pace of technological progress. This month, researchers at Georgia Tech, led by Walter de Heer, Regents' Professor in the School of Physics, created the world’s first functional graphene-based semiconductor, marking what de Heer dubbed a “Wright brothers moment” for the next-generation materials that could make up the electronic devices of the future.  (This research was also covered at Physics World, Tech Briefs, TechSpot, Freethink, McGill Daily, and Fudzilla.)

In the cosmos, the rhythm of seasons is a dance choreographed by the distinct axial tilt of each planet. The study of these celestial ballets has been the focus of astrophysicist Gongjie Li, assistant professor in the School of Physics. Funded by NASA, Li’s research delves into the reasons behind seasonal patterns, centering on the effects of a planet’s axial tilt or obliquity. Earth has an axis tilted about 23 degrees from vertical, a feature that triggers the varying intensity of sunlight across different hemispheres, resulting in changing seasons. Li articulates that planets ideally aligned axially with their orbit around the sun, assuming a circular orbit, wouldn’t bear witness to seasons due to a constant influx of sunlight.

Systems consisting of spheres rolling on elastic membranes have been used to introduce a core conceptual idea of general relativity: how curvature guides the movement of matter. However, such schemes cannot accurately represent relativistic dynamics in the laboratory because of the dominance of dissipation and external gravitational fields. A new study from School of Physics researchers demonstrates that an “active” object (a wheeled robot), which moves in a straight line on level ground and can alter its speed depending on the curvature of the deformable terrain it moves on, can exactly capture dynamics in curved relativistic spacetimes. The researchers' mapping and framework facilitate creation of a robophysical analog to a general relativistic system in the laboratory at low cost that can provide insights into active matter in deformable environments and robot exploration in complex landscapes. Researchers includes Hussain Gynai and Steven Tarr, graduate students; Emily Alicea-Muñoz, academic professional; Gongjie Li, assistant professor; and Daniel Goldman, Dunn Family Professor. 

Blimps are indeed part of this "Innovations" roundup, but it's the collaborative abilities of army ants that have led engineers from Northwestern University and the New Jersey Institute of Technology to speculate that the insects' behavioral principles and brains could one day be used to program swarms of robots. David Hu, professor in the School of Biological Sciences and the George W. Woodruff School of Mechanical Engineering (with an adjunct appointment in the School of Physics), is quoted regarding his research on fire ant raft constructions during flooding, comparing the insects to neurons in one large brain.

Georgia Tech scientists will soon have another way to search for neutrinos, those hard-to-detect, high-energy particles speeding through the cosmos that hold clues to massive particle accelerators in the universe—if researchers can find them. "The detection of a neutrino source or even a single neutrino at the highest energies is like finding a holy grail," says Nepomuk Otte, professor in the School of Physics. Otte is the principal investigator for the Trinity Demonstrator telescope that was recently built by his group and collaborators, and was designed to detect neutrinos after they get stopped within the Earth.