Multi-petahertz electronic metrology

• Published in: Nature (London) 2016-10, Vol.538 (7625), p.359-363
• Main Authors: Garg, M., Zhan, M., Luu, T. T., Lakhotia, H., Klostermann, T., Guggenmos, A., Goulielmakis, E.
• Format: Article
• Language: English
• Subjects: 639/766/1130; 639/766/400/584; Analysis; Electric current; Electric currents; Electronics; Frequencies; Humanities and Social Sciences; letter; multidisciplinary; Properties; Science; Semiconductor diodes; Silicon; Solids; Ultraviolet radiation
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature19821

Investigations using single-cycle intense optical fields to drive electron motion in bulk silicon dioxide show that the light-induced electric currents extend in frequency up to about 8 petahertz. Electronics at multi-petahertz frequencies The speed of electronics, and hence of computing, is limited by the frequencies of the electric currents that are used. Light fields can induce and manipulate electric currents at vastly higher frequencies than are achievable in conventional devices, and Eleftherios Goulielmakis and colleagues now extend this approach to reach an even faster regime. They use single-cycle intense optical fields to drive electron motion in the bulk of silicon dioxide and show that the light-induced intraband electric currents extend in frequency up to about eight petahertz. This demonstration of real-time access to the dynamic nonlinear conductivity of silicon dioxide, with the ability to directly probe and control the intraband currents on attosecond timescales, establishes intense light fields as a platform for multi-petahertz coherent electronics and points to new opportunities for fundamental studies of electron dynamics in condensed matter. The frequency of electric currents associated with charge carriers moving in the electronic bands of solids determines the speed limit of electronics and thereby that of information and signal processing 1 . The use of light fields to drive electrons promises access to vastly higher frequencies than conventionally used, as electric currents can be induced and manipulated on timescales faster than that of the quantum dephasing of charge carriers in solids 2 . This forms the basis of terahertz (10 12 hertz) electronics in artificial superlattices 2 , and has enabled light-based switches 3 , 4 , 5 and sampling of currents extending in frequency up to a few hundred terahertz. Here we demonstrate the extension of electronic metrology to the multi-petahertz (10 15 hertz) frequency range. We use single-cycle intense optical fields (about one volt per ångström) to drive electron motion in the bulk of silicon dioxide, and then probe its dynamics by using attosecond (10 −18  seconds) streaking 6 , 7 to map the time structure of emerging isolated attosecond extreme ultraviolet transients and their optical driver. The data establish a firm link between the emission of the extreme ultraviolet radiation and the light-induced intraband, phase-coherent electric currents that extend in frequency up to about eight p