title: Semimetallization of dielectrics in strong optical fields.
abstract: At the heart of ever growing demands for faster signal processing is ultrafast charge transport and control by electromagnetic fields in semiconductors. Intense optical fields have opened fascinating avenues for new phenomena and applications in solids. Because the period of optical fields is on the order of a femtosecond, the current switching and its control by an optical field may pave a way to petahertz optoelectronic devices. Lately, a reversible semimetallization in fused silica on a femtosecond time scale by using a few-cycle strong field (~1 V/Å) is manifested. The strong Wannier-Stark localization and Zener-type tunneling were expected to drive this ultrafast semimetallization. Wider spread of this technology demands better understanding of whether the strong field behavior is universally similar for different dielectrics. Here we employ a carrier-envelope-phase stabilized, few-cycle strong optical field to drive the semimetallization in sapphire, calcium fluoride and quartz and to compare this phenomenon and show its remarkable similarity between them. The similarity in response of these materials, despite the distinguishable differences in their physical properties, suggests the universality of the physical picture explained by the localization of Wannier-Stark states. Our results may blaze a trail to PHz-rate optoelectronics.
authors.affiliation: Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.|Max Planck Center for Attosecond Science, Max Planck POSTECH/Korea Res. Init., Pohang, 37673, Republic of Korea.
authors.forename: Ojoon
authors.initials: O
authors.lastname: Kwon
authors.affiliation: Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Paasch-Colberg
authors.affiliation: Center for Nano-Optics (CeNO) and Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
authors.forename: Vadym
authors.initials: V
authors.lastname: Apalkov
authors.affiliation: Department of Physics, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Bum-Kyu
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Physics, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Ju-Jin
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Center for Nano-Optics (CeNO) and Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
authors.forename: Mark I
authors.initials: MI
authors.lastname: Stockman
authors.affiliation: Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.|Max Planck Center for Attosecond Science, Max Planck POSTECH/Korea Res. Init., Pohang, 37673, Republic of Korea.
authors.forename: D
authors.initials: D
authors.lastname: Kim