653 research outputs found
Realization of Zero-Refractive-Index Lens with Ultralow Spherical Aberration
Optical complex materials offer unprecedented opportunity to engineer
fundamental band dispersion which enables novel optoelectronic functionality
and devices. Exploration of photonic Dirac cone at the center of momentum space
has inspired an exceptional characteristic of zero-index, which is similar to
zero effective mass in fermionic Dirac systems. Such all-dielectric zero-index
photonic crystals provide an in-plane mechanism such that the energy of the
propagating waves can be well confined along the chip direction. A
straightforward example is to achieve the anomalous focusing effect without
longitudinal spherical aberration, when the size of zero-index lens is large
enough. Here, we designed and fabricated a prototype of zero-refractive-index
lens by comprising large-area silicon nanopillar array with plane-concave
profile. Near-zero refractive index was quantitatively measured near 1.55 um
through anomalous focusing effect, predictable by effective medium theory. The
zero-index lens was also demonstrated to perform ultralow longitudinal
spherical aberration. Such IC compatible device provides a new route to
integrate all-silicon zero-index materials into optical communication, sensing,
and modulation, and to study fundamental physics on the emergent fields of
topological photonics and valley photonics.Comment: 14 pages, 4 figure
Tired Light Denies the Big Bang
More and more problems related to Big Bang have been appeared in recent years. All the problems are due to the Doppler interpretation of redshift. The “tired light” theory, proposed in 1929 by Zwicky and most recently developed by Shao in 2013, gives a new explanation for redshift. The theory has shown that the redshift is induced from the energy loss of photons by the interaction with material particles on their journey through cosmological space. The basic principles related to the energy transfer are mainly the mass-energy equivalence and the Lorentz theory. Problems, such as super velocity, the horizon problem, the cosmological microwave background radiation, and Olbers’ paradox, vanish in the cosmological model of “tired light” theory. The model describes a boundless and timeless Cosmos
An improved plating assay for determination of phage titer
Phage is a virus that is parasitic on bacteria. It is very important to determine the titer of test sample in the study of phage. In this study, an improved plating assay was developed for detection of the number of recombinant phage Cap-T7 present in a test solution at a certain dilution point by counting the plaque forming units. The data demonstrated that the improved plating assay is fast, useful, and convenient for the determination of the phage titer in a sample.Keywords: Phage Cap-T7, detection method, plaque forming unit
Discrimination of Coherent States via Atom-Field Interaction without Rotation Wave Approximation
The quantum state discrimination is an important part of quantum information
processing. We investigate the discrimination of coherent states through
Jaynes-Cummings (JC) model interaction between the field and the ancilla
without rotation wave approximation (RWA). We show that the minimum failure
probability can be reduced as RWA is eliminated from JC model and the non-RWA
terms accompanied by the quantum effects of fields (e.g. the virtual photon
process in the JC model without RWA) can enhance the state discrimination. The
JC model without RWA for unambiguous state discrimination is superior to
ambiguous state discrimination, particularly when the number of sequential
measurements increases. Unambiguous state discrimination implemented via the
non-RWA JC model is beneficial to saving resource cost.Comment: 8 pages, 4 figures. Accepted for publication in Communications in
Theoretical Physic
Discriminating bipartite mixed states by local operations
Unambiguous state discrimination of two mixed bipartite states via local
operations and classical communications (LOCC) is studied and compared with the
result of a scheme realized via global measurement. We show that the success
probability of a global scheme for mixed-state discrimination can be achieved
perfectly by the local scheme. In addition, we simulate this discrimination via
a pair of pure entangled bipartite states. This simulation is perfect for local
rather than global schemes due to the existence of entanglement and global
coherence in the pure states. We also prove that LOCC protocol and the
sequential state discrimination (SSD) can be interpreted in a unified view. We
then hybridize the LOCC protocol with three protocols (SSD, reproducing and
broadcasting) relying on classical communications. Such hybridizations extend
the gaps between the optimal success probability of global and local schemes,
which can be eliminated only for the SSD rather than the other two protocols
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