arXiv subjects

Y. B. Liu

Publications and source records attributed to Y. B. Liu.

3 recordsLinked to original sources

arXiv2016

Distributed Data-Processing Pipeline for Mingantu Ultrawide Spectral Radioheliograph

The Chinese Spectral RadioHeliograph (CSRH) is a synthetic aperture radio interferometer built in Inner Mongolia, China. As a solar-dedicated interferometric array, CSRH is capable of producing high quality radio images at frequency range from 400 MHz to 15 GHz with high temporal, spatial, and spectral resolution.To implement high cadence imaging at wide-band and obtain more than 2 order higher multiple frequencies, the implementation of the data processing system for CSRH is a great challenge. It is urgent to build a pipeline for processing massive data of CSRH generated every day. In this paper, we develop a high performance distributed data processing pipeline (DDPP) built on the OpenCluster infrastructure for processing CSRH observational data including data storage, archiving, preprocessing, image reconstruction, deconvolution, and real-time monitoring. We comprehensively elaborate the system architecture of the pipeline and the implementation of each subsystem. The DDPP is automatic, robust, scalable and manageable. The processing performance under multi computers parallel and GPU hybrid system meets the requirements of CSRH data processing. The study presents an valuable reference for other radio telescopes especially aperture synthesis telescopes, and also gives an valuable contribution to the current and/or future data intensive astronomical observations.

astro-ph.IM↗

arXiv2009

On-demand Entanglement Source with Spatial Phase Modulation

The polarization entanglement photon pairs generated from the biexciton cascade decay in a single semiconductor quantum dot is corrupted by the position-dependent (time-dependent) phase difference of the two polarization mode due to the fine structure splitting. We show that, by taking voltage ramping to an electro-optic modulator, such phase-difference can be removed. In our first proposed set-up, two photons are sent to two separate Pockels cell under reverse voltage ramping, as a result, the position-dependent phase difference between the two polarization mode is removed in the outcome state. In our second proposed set-up, the polarization of the first photon is flipped and then both photons fly into the same Pokels cell. Since we only need to separate the two photons rather than separate the two polarization modes, our schemes are robust with respect to fluctuations of the optical paths.

quant-ph↗

arXiv2007

Study of Hadron Scattering Using an Asymmetric Box

We propose to study hadron-hadron scattering using lattice QCD in an asymmetric box which allows one to access more non-degenerate low-momentum modes for a given volume. The conventional Lüscher's formula applicable in a symmetric box is modified accordingly. To illustrate the feasibility of this approach, pion-pion elastic scattering phase shifts in the I=2, J=0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. After the chiral and continuum extrapolation, we find that our quenched results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. Agreement is also found when compared with previous theoretical results from lattice and other means. Moreover, with the usage of asymmetric volume, we are able to compute the scattering phases in the low-momentum range (pion three momentum less than about 350MeV in the center of mass frame) for over a dozen values of the pion three-momenta, much more than using the conventional symmetric box with comparable volume.

hep-lat↗