News from Nanotechjapan


Light-Matter Energy Transfer in Solids Characterized at Attosecond Accuracy---Future Possibility of a Switch for Light-Wave Electronics---

 Tsukuba University, Ibaraki, Japan issued a press release on 24th May 2016, that Professor Kazuhiro Yabana and his colleagues of Center for Computational Sciences of the university succeeded in characterizing light-matter energy transfer in solids at attosecond accuracy with a team of Ludwig Maximilians Universität (LMU). The results were published in Nature*, and LMU also issued a press release with more emphasis on electronic switching.

 Present electronic circuits are approaching their clock rate limitation at some billion switching cycles per second, due to the heat generation. On the other hand, light waves are expected to form the basis for future electronic switching without overheating.

 The researchers have employed laser pulses with the wavelength of 750 nm, each lasting for a few femtoseconds (fs; 1 fs is a millionth of a billionth of a second) to perturb electrons in glass. The light pulse consists of a single oscillation of the field, so the electrons are moved left and right only once. The full temporal characterization of the light field after transmission through the thin glass plate reveals that electrons react to the incoming light within a few tens of attoseconds (as; 1 as=10−18 s). 
 Detailed understandings of the observed phenomena were backed up by a novel first principle simulation on K-computer. These findings confirm future possibility of a switch for light-driven electronics.

*A. Sommer, E. M. Bothschafter, S. A. Sato, C. Jakubeit, T. Latka, O. Razskazovskaya, H. Fattahi, M. Jobst, W. Schweinberger, V. Shirvanyan, V. S. Yakovlev, R. Kienberger, K. Yabana, N. Karpowicz, M. Schultze & F. Krausz, "Attosecond nonlinear polarization and light-matter energy transfer in solids",  Nature (2016) doi:10.1038/nature17650; Published online 23 May 2016