Nanowerk December 14, 2020
The mismatch between electronic systems and optical systems means that every time a signal converts from one to the other, inefficiency creeps into the system. A team of researchers in the US (UT Austin, UMass Lowell, Purdue University) has found a way to create more efficient metamaterials using semiconductors and a novel aspect of physics that amplifies the activity of electrons. They have demonstrated optical phenomenon of “ballistic resonance” resulting from the interplay between free charge motion in confining geometries and periodic driving electromagnetic fields, which can be utilized to achieve negative permittivity at frequencies well above the bulk plasma frequency. They demonstrated all-semiconductor hyperbolic metamaterials operating at frequencies 60% above the plasma frequency of the constituent doped semiconductor “metallic” layer. Ballistic resonance will therefore enable the realization and deployment of various applications that rely on local field enhancement and emission modulation, typically associated with plasmonic materials, in new materials platforms…read more. Open Access TECHNICAL ARTICLE
Schematic of the ballistic metamaterial, (b) cross-sectional SEM image of the sample HMM1…Credit: Optica Vol. 7, Issue 12, pp. 1773-1780 (2020)