Localized and collective magnetoplasmon excitations in AlGaN/GaN-based grating-gate terahertz modulators

K. Nogajewski , J. Lusakowski , Wojciech Knap (1) , V. V. Popov , Frederic Teppe (1) , S. L. Rumyantsev , M. S. Shur

1 L2C - Laboratoire Charles Coulomb

Magnetotransport and magnetooptics investigations of plasmon excitations in large-area grating-gate terahertz modulators based on AlGaN/GaN high-electron-mobility transistors with different grating-gate duty cycle are reported. We demonstrate that the effect of the gate potential on the ungated region extends beyond the conventional fringing effect distance, ranging over 250-350 nm instead of expected 26-30 nm. This phenomenon enables excitation of the localized gated magnetoplasmon modes only if the inter-finger spacing in the grating gate exceeds 350 nm. For narrower slits, only the collective gated magnetoplasmon modes extending over the entire period of the structure can be excited.

Mots clés: aluminium compounds; gallium compounds; galvanomagnetic effects; high electron mobility transistors; III-V semiconductors; plasmonics; wide band gap semiconductors

Domaines: Science des matériaux [cond-mat.mtrl-sci]

K. Nogajewski, J. Lusakowski, Wojciech Knap, V. V. Popov, Frederic Teppe, et al.. Localized and collective magnetoplasmon excitations in AlGaN/GaN-based grating-gate terahertz modulators. Applied Physics Letters, 2011, 99 (21), pp.213501. ⟨10.1063/1.3663626⟩. ⟨hal-00814472⟩