Edge and bulk effects in the Terahertz-photoconductivity of an antidot superlattice

We investigate the Terahertz(THz)-response of a square antidot superlattice by means of photoconductivity measurements using a Fourier-transform-spectrometer. We detect, spectrally resolved, the cyclotron resonance and the fundamental magnetoplasmon mode of the periodic superlattice. In the dissipative transport regime both resonances are observed in the photoresponse. In the adiabatic transport regime, at integer filling factor $\nu =2$, only the cyclotron resonance is observed. From this we infer that different mechanisms contribute to converting the absorption of THz-radiation into photoconductivity in the cyclotron and in the magnetoplasmon resonances, respectively.Comment: 15 pages, 4 figures, submitted to Phys. Rev.

Discussion of 'Geomechanical modeling of the nucleation process of Australia's 1989 M5.6 Newcastle earthquake' by C.D. Klose [Earth Planet. Sci. Lett. 256 (2007) 547-553]

On the basis of a numerical simulation, Klose [Earth Planet. Sci. Lett. 256: 547-553 (2007)] proposed that the MW = 5.2-5.6 earthquake that nucleated beneath Newcastle (New South Wales, Australia) at 10.30 AM December 28, 1989 (AEST), was the result of 200yr of coal mining in the region. We argue here that Klose's [Earth Planet. Sci. Lett. 256: 547-553 (2007)] ultimate conclusion is not supported by his own model or by available geological and seismic data. In particular, the 1989 Newcastle earthquake was not anomalous with respect to regional seismic activity