5,765 research outputs found
Spin correlated interferometry for polarized and unpolarized photons on a beam splitter
Spin interferometry of the 4th order for independent polarized as well as
unpolarized photons arriving simultaneously at a beam splitter and exhibiting
spin correlation while leaving it, is formulated and discussed in the quantum
approach. Beam splitter is recognized as a source of genuine singlet photon
states. Also, typical nonclassical beating between photons taking part in the
interference of the 4th order is given a polarization dependent explanation.Comment: RevTeX, 19 pages, 1 ps figure, author web page at
http://m3k.grad.hr/pavici
Field-Trial of Machine Learning-Assisted Quantum Key Distribution (QKD) Networking with SDN
We demonstrated, for the first time, a machine-learning method to assist the
coexistence between quantum and classical communication channels.
Software-defined networking was used to successfully enable the key generation
and transmission over a city and campus network
An experimental investigation of criteria for continuous variable entanglement
We generate a pair of entangled beams from the interference of two amplitude
squeezed beams. The entanglement is quantified in terms of EPR-paradox [Reid88]
and inseparability [Duan00] criteria, with observed results of and , respectively. Both results clearly beat the standard quantum
limit of unity. We experimentally analyze the effect of decoherence on each
criterion and demonstrate qualitative differences. We also characterize the
number of required and excess photons present in the entangled beams and
provide contour plots of the efficacy of quantum information protocols in terms
of these variables.Comment: 4 pages, 5 figure
RF-MEMS switch actuation pulse optimization using Taguchi's method
Copyright @ 2011 Springer-VerlagReliability and longevity comprise two of the most important concerns when designing micro-electro-mechanical-systems (MEMS) switches. Forcing the switch to perform close to its operating limits underlies a trade-off between response bandwidth and fatigue life due to the impact force of the cantilever touching its corresponding contact point. This paper presents for first time an actuation pulse optimization technique based on Taguchiâs optimization method to optimize the shape of the actuation pulse of an ohmic RF-MEMS switch in order to achieve better control and switching conditions. Simulation results show significant reduction in impact velocity (which results in less than 5 times impact force than nominal step pulse conditions) and settling time maintaining good switching speed for the pull down phase and almost elimination of the high bouncing phenomena during the release phase of the switch
Resistive damping implementation as a method to improve controllability in stiff ohmic RF-MEMS switches
This paper presents in detail the entire procedure of calculating the bias resistance of an ohmic RF-MEMS switch, controlled under resistive damping (charge drive technique). In case of a very stiff device, like the North Eastern University switch, the actuation control under resistive damping is the only way to achieve controllability. Due to the short switching time as well as the high actuation voltage, it is not practical to apply a tailored control pulse (voltage drive control technique). Implementing a bias resistor of 33 MΩ in series with the voltage source, the impact velocity of the cantilever has been reduced 80 % (13.2 from 65.9 cm/s), eliminating bouncing and high initial impact force during the pull-down phase. However, this results in an affordable cost of switching time increase from 2.38 to 4.34 Όs. During the release phase the amplitude of bouncing has also been reduced 34 % (174 from 255 nm), providing significant improvement in both switching operation phases of the switch. © 2013 Springer-Verlag Berlin Heidelberg
Concise theory of chiral lipid membranes
A theory of chiral lipid membranes is proposed on the basis of a concise free
energy density which includes the contributions of the bending and the surface
tension of membranes, as well as the chirality and orientational variation of
tilting molecules. This theory is consistent with the previous experiments
[J.M. Schnur \textit{et al.}, Science \textbf{264}, 945 (1994); M.S. Spector
\textit{et al.}, Langmuir \textbf{14}, 3493 (1998); Y. Zhao, \textit{et al.},
Proc. Natl. Acad. Sci. USA \textbf{102}, 7438 (2005)] on self-assembled chiral
lipid membranes of DCPC. A torus with the ratio between its two
generated radii larger than is predicted from the Euler-Lagrange
equations. It is found that tubules with helically modulated tilting state are
not admitted by the Euler-Lagrange equations, and that they are less
energetically favorable than helical ripples in tubules. The pitch angles of
helical ripples are theoretically estimated to be about 0 and
35, which are close to the most frequent values 5 and
28 observed in the experiment [N. Mahajan \textit{et al.}, Langmuir
\textbf{22}, 1973 (2006)]. Additionally, the present theory can explain twisted
ribbons of achiral cationic amphiphiles interacting with chiral tartrate
counterions. The ratio between the width and pitch of twisted ribbons is
predicted to be proportional to the relative concentration difference of left-
and right-handed enantiomers in the low relative concentration difference
region, which is in good agreement with the experiment [R. Oda \textit{et al.},
Nature (London) \textbf{399}, 566 (1999)].Comment: 14 pages, 7 figure
The Mach-Zehnder and the Teleporter
We suggest a self-testing teleportation configuration for photon q-bits based
on a Mach-Zehnder interferometer. That is, Bob can tell how well the input
state has been teleported without knowing what that input state was. One could
imagine building a "locked" teleporter based on this configuration. The
analysis is performed for continuous variable teleportation but the arrangement
could equally be applied to discrete manipulations.Comment: 4 pages, 5 figure
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