arXiv subjects

Natalia V. Demarina

Publications and source records attributed to Natalia V. Demarina.

2 recordsLinked to original sources

arXiv2006

Suppressed absolute negative conductance and generation of high-frequency radiation in semiconductor superlattices

We show that space-charge instabilities (electric field domains) in semiconductor superlattices are the attribute of absolute negative conductance induced by small constant and large alternating electric fields. We propose the efficient method for suppression of this destructive phenomenon in order to obtain a generation at microwave and THz frequencies in devices operating at room temperature. We theoretically proved that an unbiased superlattice with a moderate doping subjected to a microwave pump field provides a strong gain at third, fifth, seventh, etc. harmonics of the pump frequency in the conditions of suppressed domains.

cond-mat.mes-hall↗

arXiv2005

Generation of high-frequency radiation in semiconductor superlattices with suppressed space-charge instabilities

We theoretically investigated the scheme allowing to avoid destructive space-charge instabilities and to obtain a strong gain at microwave and THz frequencies in semiconductor superlattice devices. Superlattice is subjected to a microwave field and a generation is achieved at some odd harmonics of the pump frequency. Gain arises because of parametric amplification seeded by harmonic generation. Negative differential conductance (NDC) is not a necessary condition for the generation. For the mode of operation with NDC, a limited space-charge accumulation does not sufficiently reduce the gain.

cond-mat.mes-hall↗