Speeding up electronics to light frequencies

Modern information processing allows for breathtaking switching rates of about a 100 billion cycles per second. New results from the Laboratory for Attosecond Physics (LAP) of Prof. Ferenc Krausz (Max Planck Institute of Quantum Optics (MPQ), Garching, and Ludwig-Maximilians-Universität Munich) could pave the way towards signal processing several orders of magnitude faster. In two groundbreaking complementary experiments a collaboration led by LAP-physicists has demonstrated that, under certain conditions, ultrashort light pulses of extremely high intensity can induce electric currents in otherwise insulating dielectric materials (Nature, AOP, 5 December 2012). Furthermore, they provided evidence that the fast oscillations of the electric field instantly alter the electrical and optical properties of the material, and that these changes can be reversed on a femtosecond (10-15 s) time scale (Nature, same issue). This opens the door for signal processing rates reaching the petahertz (1015 Hz) domain, about 10,000 times faster than it is possible with the best state-of-the-art solid state microchips. The experiments were carried out by researchers from MPQ, LMU, and Technische Universität München, in close cooperation with the theoretical group of Prof. Mark Stockman (Georgia State University, Atlanta).