10,470 research outputs found
The consistency of estimator under fixed design regression model with NQD errors
In this article, basing on NQD samples, we investigate the fixed design
nonparametric regression model, where the errors are pairwise NQD random
errors, with fixed design points, and an unknown function. Nonparametric
weighted estimator will be introduced and its consistency is studied. As
special case, the consistency result for weighted kernel estimators of the
model is obtained. This extends the earlier work on independent random and
dependent random errors to NQD case
Generation of Narrow-Band Polarization-Entangled Photon Pairs for Atomic Quantum Memories
We report an experimental realization of a narrow-band polarization-entangled
photon source with a linewidth of 9.6 MHz through cavity-enhanced spontaneous
parametric down-conversion. This linewidth is comparable to the typical
linewidth of atomic ensemble based quantum memories. Single-mode output is
realized by setting a reasonable cavity length difference between different
polarizations, using of temperature controlled etalons and actively stabilizing
the cavity. The entangled property is characterized with quantum state
tomography, giving a fidelity of 94% between our state and a maximally
entangled state. The coherence length is directly measured to be 32 m through
two-photon interference.Comment: 4 pages, 4 figure
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