Bloch oscillations in a semiconductor superlattice shifting from capacitive to conductive responses with electric-field-induced interminiband mixing
Abstract
We investigate the initial phase of Bloch oscillations in a GaAs-based superlattice designed for fine bias control of interminiband mixing. The type of oscillation current, determined from terahertz emission with the time origin (t=0), is found to shift gradually from damped cos ωBt to damped sin ωBt (ωB/2π: Bloch frequency) as the dc bias electric field is increased. This demonstrates a continuous transition between the capacitive and conductive responses, which have been previously reported in the two regimes where electron wavefunctions are Wannier–Stark localized within a nearly isolated miniband and delocalized by substantial interminiband mixing, respectively.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (6)
Takeya Unuma
Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology 1 , 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188,
Keita Okada
Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology 1 , 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188,
Kosuke Ueda
Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology 1 , 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188,
Nobuko Hino
Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology 1 , 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188,
Naomi Nagai
Institute of Industrial Science, The University of Tokyo 2 , 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505,
Kazuhiko Hirakawa
Institute of Industrial Science, The University of Tokyo 2 , 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505,