11,746 research outputs found
Quantum phase gate for photonic qubits using only beam splitters and post-selection
We show that a beam splitter of reflectivity one-third can be used to realize
a quantum phase gate operation if only the outputs conserving the number of
photons on each side are post-selected.Comment: 6 pages RevTex, including one figur
Demonstration of an optical quantum controlled-NOT gate without path interference
We report the first experimental demonstration of an optical quantum
controlled-NOT gate without any path interference, where the two interacting
path interferometers of the original proposals (Phys. Rev. A {\bf 66}, 024308
(2001), Phys. Rev. A {\bf 65}, 012314 (2002)) have been replaced by three
partially polarizing beam splitters with suitable polarization dependent
transmittances and reflectances. The performance of the device is evaluated
using a recently proposed method (Phys. Rev. Lett. {\bf 94}, 160504 (2005)), by
which the quantum process fidelity and the entanglement capability can be
estimated from the 32 measurement results of two classical truth tables,
significantly less than the 256 measurement results required for full quantum
tomography.Comment: 4 pages, 3 figure
OAO/ISLE Near-IR Spectroscopy of IRAS Galaxies
We present the results of the near-infrared (IR) spectroscopy of nine IRAS
galaxies (NGC 1266, NGC 1320, NGC 2633, NGC 2903, NGC 3034, Mrk 33, NGC 7331,
NGC 7625, NGC 7714) with the ISLE imager and spectrograph mounted on the
Okayama Astrophysical Observatory 1.88 m telescope. [Fe II] 1.257 um and Pa
beta emission lines were observed for the whole sample while H2 2.121 um and Br
gamma lines were additionally obtained for two sources, whose flux ratios are
used as a diagnostic tool of dominant energy sources of the galaxies. We find
that the nucleus of NGC 1266 is most likely a low ionization nuclear
emission-line region (LINER), while NGC 2633 and NGC 2903 possibly harbor
active galactic nuclei (AGNs). No AGN or LINER signal is found for other
objects. In addition, we find the spectral features which is indicative of some
unusual phenomena occurring in the galaxies, such as the large [Fe II] line
widths compared to the local escape velocity in NGC 1266. The present work
shows the potential ability of the ISLE to shed new light on the nature of
infrared galaxies, either through a statistical survey of galaxies or an
exploration of spectral features found in individual objects.Comment: Accepted for publication in PAS
- …