We have measured the electric signal downconverted from a terahertz frequency by an unbiased high mobility two-dimensional electron-gas (2DEG) device. The 2DEG was confined in an asymmetric plasmonic microcavity, and the radiation frequency was continuously tuned in the 0.2-0.4 THz range. The presence of resonant peaks at three frequencies corresponding to three plasma oscillation modes of the ungated 2DEG clearly points to the intrinsic nature of the hydrodynamic nonlinearity responsible for the downconversion as opposed to previously proposed plasmonic cavity configurations where the 2DEG oscillates under the metal gate that also acts as the source of the nonlinearity.
Downconversion of terahertz radiation due to intrinsic hydrodynamic nonlinearity of a two-dimensional electron plasma
Giliberti V;Di Gaspare A;Giovine E;Ortolani M;Sorba L;Biasiol G;
2015
Abstract
We have measured the electric signal downconverted from a terahertz frequency by an unbiased high mobility two-dimensional electron-gas (2DEG) device. The 2DEG was confined in an asymmetric plasmonic microcavity, and the radiation frequency was continuously tuned in the 0.2-0.4 THz range. The presence of resonant peaks at three frequencies corresponding to three plasma oscillation modes of the ungated 2DEG clearly points to the intrinsic nature of the hydrodynamic nonlinearity responsible for the downconversion as opposed to previously proposed plasmonic cavity configurations where the 2DEG oscillates under the metal gate that also acts as the source of the nonlinearity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.