On-chip terahertz spectroscopy of magnetoplasmons in a two-dimensional electron gas

We report observations of magnetoplasmons at frequencies up to 400 GHz in gated two-dimensional electron gases (2DEG) at low temperature (∼ 2K). We observed bulk magnetoplasmons for frequencies greater than the cyclotron resonance frequency, and attributed resonances occurring at frequencies below the cyclotron resonance to formation of edge magnetoplasmons (EMPs). Our full-wave 3D electromagnetic simulation results are in good agreement with the experimental findings, allowing us to predict the spatial distribution of both bulk and edge magnetoplasmon modes in the 2DEG

Terahertz magnetoplasmon resonances in coupled cavities formed in a gated two-dimensional electron gas

We report on both experiments and theory of low-terahertz frequency range (up to 400 GHz) magnetoplasmons in a gated two-dimensional electron gas at low (<4K) temperatures. The evolution of magnetoplasmon resonances was observed as a function of magnetic field at frequencies up to ∼400 GHz. Full-wave 3D simulations of the system predicted the spatial distribution of plasmon modes in the 2D channel, along with their frequency response, allowing us to distinguish those resonances caused by bulk and edge magnetoplasmons in the experiments. Our methodology is anticipated to be applicable to the low temperature (<4K) on-chip terahertz measurements of a wide range of other low-dimensional mesoscopic systems

The Milliarcsecond Structure of Radio Galaxies and Quasars

Hybrid maps of the nuclei of radio galaxies and quasars show a variety of morphologies. Among compact sources, two structures are common: an asymmetric, “core-jet” morphology (eg, 3C 273), and an “equal double” morphology with two separated, similar components (eg, CTD 93). The nuclei of extended, double radio galaxies generally have a core-jet morphology with the jet directed toward one of the outer components

Abscess Formation Following Spilled Gallstones During Laparoscopic Cholecystectomy

A review of the English literature concerning spilled gallstones during laparoscopic cholecystectomy is compared with one institution's experience of four cases during 1,726 laparoscopic cholecystectomies performed over a four-year period. Strategies regarding management and treatment are discussed