[11p-N404-1~9] 4.6 Terahertz Photonics

▲ [11p-N404-7] Nanoscale Transistors for On-Chip Sourcing of Terahertz Plasmons

Bilal Barut^1,2, Xavier Cantos-Roman³, Chun-Pui Kwan^1,2, Ripudaman Dixit¹, Nargess Arabchigavkani^1,2, Shenchu Yin¹, Jubin Nathawat¹, Keke He¹, Michael Randle¹, Farah Vandrevala¹, Takeyoshi Sugaya⁴, Erik Einarsson^1,5, Josep Jornet³, 〇Jonathan P Bird¹, Gregory Aizin⁶ (1.Department of Electrical Engineering, University at Buffalo, the State University of New York, Buffalo, NY 14260, USA, 2.Department of Physics, University at Buffalo, the State University of New York, Buffalo, NY 14260, USA, 3.Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA, 4.Global Zero Emission Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 Japan, 5.Department of Materials Design and Innovation, University at Buffalo, the State University of New York, Buffalo, NY 14260, USA, 6.Kingsborough College, The City University of New York, NY 11235, USA)

Keywords:terahertz electronics, plasmonic sources, nanoscale transistors

Plasma oscillations in semiconductors occur at terahertz (THz) frequencies, and represent a potential path to implement ultra-fast electronic devices and circuits. Here, we present an approach to generating on-chip THz signals that relies on the stabilization of plasma waves in nanoscale transistors, designed with very specific structural asymmetry. A hydrodynamic treatment of the electron fluid in the transistors shows how their asymmetry supports the amplification of plasma waves, giving rise to pronounced negative differential conductance (NDC) once this THz plasma mode is stabilized. A proof-of-concept demonstration of this effect is provided in high-mobility In0.8Ga0.2As transistors, which exhibit NDC in accordance with their structural asymmetry. The NDC onsets once the drift velocity in the channel reaches a threshold value, triggering the initial plasma instability. It can also persist beyond room temperature (to at least 75C) when the gating is configured to maximize the instability conditions. Our findings therefore represent a significant step forward for efforts to develop active components for THz electronics.