119 research outputs found
Tailoring chaotic motion of microcavity photons in ray and wave dynamics by tuning the curvature of space
Microcavity photon dynamics in curved space is an emerging interesting area
at the crossing point of nanophotonics, chaotic science and non-Euclidean
geometry. We report the sharp difference between the regular and chaotic
motions of cavity photons subjected to the varying space curvature. While the
island modes of regular motion rise in the phase diagram in the curved space,
the chaotic modes show special mechanisms to adapt to the space curvature,
including the fast diffusion of ray dynamics, and the localization and
hybridization of the Husimi wavepackets among different periodic orbits. These
obser-vations are unique effects enabled by the combination of the chaotic
trajectory, the wave nature of light and the non-Euclidean orbital motion, and
therefore make the system a versatile optical simulator for chaotic science
under quan-tum mechanics in curved space-time
Direct Manipulation of quantum entanglement from the non-Hermitian nature of light-matter interaction
Biphoton process is an essential benchmark for quantum information science
and technologies, while great efforts have been made to improve the coherence
of the system for better quantum correlations. Nevertheless, we find that the
non-Hermitian features induced by the atomic quantum interference could be well
employed for the direct control of entanglement. We report the demonstration of
exceptional point (EP) in biphotons by measuring the light-atom interaction as
a natural non-Hermitian system, in which the electromagnetically induced
transparency regime provides a powerful mechanism to precisely tune the
non-Hermitian coupling strength. Such biphoton correlation is tuned within an
unprecedented large range from Rabi oscillation to
antibunching-exponential-decay, also indicating high-dimensional entanglement
within the strong and weak light-matter coupling regimes. The EP at the
transition point between the two regimes is clearly observed with the biphoton
quantum correlation measurements, exhibiting a single exponential decay and
manifesting the coalesced single eigenstate. Our results provide a unique
method to realize the controllability of natural non-Hermitian processes
without the assistance of artificial photonic structures, and paves the way for
quantum control by manipulating the non-Hermitian features of the light-matter
interaction
Seeing is Believing: Detecting Sybil Attack in FANET by Matching Visual and Auditory Domains
The flying ad hoc network (FANET) will play a crucial role in the B5G/6G era
since it provides wide coverage and on-demand deployment services in a
distributed manner. The detection of Sybil attacks is essential to ensure
trusted communication in FANET. Nevertheless, the conventional methods only
utilize the untrusted information that UAV nodes passively ``heard'' from the
``auditory" domain (AD), resulting in severe communication disruptions and even
collision accidents. In this paper, we present a novel VA-matching solution
that matches the neighbors observed from both the AD and the ``visual'' domain
(VD), which is the first solution that enables UAVs to accurately correlate
what they ``see'' from VD and ``hear'' from AD to detect the Sybil attacks.
Relative entropy is utilized to describe the similarity of observed
characteristics from dual domains. The dynamic weight algorithm is proposed to
distinguish neighbors according to the characteristics' popularity. The
matching model of neighbors observed from AD and VD is established and solved
by the vampire bat optimizer. Experiment results show that the proposed
VA-matching solution removes the unreliability of individual characteristics
and single domains. It significantly outperforms the conventional RSSI-based
method in detecting Sybil attacks. Furthermore, it has strong robustness and
achieves high precision and recall rates.Comment: 7 pages, 9 figures, 1 tabl
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