Last December, the journal Science listed left-handed materials as one of its Top Ten Breakthroughs of 2003. In the topsy-turvy world of advanced physics these unusual materials, first created by a UCSD research group three years ago, can bend light, and other kinds of electromagnetic radiation “backward,” reversing many of the physical properties that govern the behavior of ordinary materials.

The UCSD group has partnered with researchers at UCLA and Imperial College London, to make similar materials. Although these are not left-handed they have unique physical qualities and respond magnetically in the terahertz range, a set of frequencies between infrared rays and microwave rays.

Terahertz rays are lower in frequency and much less damaging than X-rays and could have many potential applications including biomedical imaging. The Department of Defense is also interested in terahertz rays. “Certain chemical and bio-terror agents, like anthrax happen to have a distinct absorption in the terahertz range,” explains Willie Padilla, a graduate student in the laboratory of UCSD professor of physics Dimitri Basov, “and since terahertz can penetrate clothing, it is also of interest for airport screening of weapons and explosives.”