Search Results
Sound-driven single-electron transfer in a circuit of coupled quantum rails
2019, Takada, Shintaro, Edlbauer, Hermann, Lepage, Hugo V., Wang, Junliang, Mortemousque, Pierre-André, Georgiou, Giorgos, Barnes, Crispin H. W., Ford, Christopher J. B., Yuan, Mingyun, Santos, Paulo V., Waintal, Xavier, Ludwig, Arne, Wieck, Andreas D., Urdampilleta, Matias, Meunier, Tristan, Bäuerle, Christopher
Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits. © 2019, The Author(s).
Author Correction: Surface acoustic wave nebulization improves compound selectivity of low-temperature plasma ionization for mass spectrometry
2021, Kiontke, Andreas, Roudini, Mehrzad, Billig, Susan, Fakhfouri, Armaghan, Winkler, Andreas, Birkemeyer, Claudia
Correction to: Scientific Reports https://doi.org/10.1038/s41598-021-82423-w, published online 03 February 2021
Infrasound - The cause of strong Polar Mesosphere Winter Echoes?
2006, Kirkwood, S., Chilson, P., Belova, E., Dalin, P., Häggström, I., Rietveld, M., Singer, W.
The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that the scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms-1 or more, and high aspect sensitivity, with echo arrival angles spread over as little as 0.3°. ESRAD also detected, on some occasions, discrete scattering regions moving across the field of view with periodicities of a few seconds. The very narrow, vertically directed beam of the more powerful EISCAT radar allowed measurements of the spectral widths of the radar echoes both inside the PMWE and from the background plasma above and below the PMWE. Spectral widths inside the PMWE were found to be indistinguishable from those from the background plasma. We propose that scatter from highly-damped ion-acoustic waves generated by partial reflection of infrasonic waves provides a reasonable explanation of the characteristics of the very strong PMWE reported here.
ASAMgpu V1.0 - A moist fully compressible atmospheric model using graphics processing units (GPUs)
2012, Horn, S.
In this work the three dimensional compressible moist atmospheric model ASAMgpu is presented. The calculations are done using graphics processing units (GPUs). To ensure platform independence OpenGL and GLSL are used, with that the model runs on any hardware supporting fragment shaders. The MPICH2 library enables interprocess communication allowing the usage of more than one GPU through domain decomposition. Time integration is done with an explicit three step Runge-Kutta scheme with a time-splitting algorithm for the acoustic waves. The results for four test cases are shown in this paper. A rising dry heat bubble, a cold bubble induced density flow, a rising moist heat bubble in a saturated environment, and a DYCOMS-II case.