5,002 research outputs found
Inherent Mach-Zehnder interference with "which-way" detection for single particle scattering in one dimension
We study the coherent transport of single photon in a one-dimensional
coupled-resonator-array, "non-locally" coupled to a two-level system. Since its
inherent structure is a Mach-Zehnder interferometer, we explain the destructive
interference phenomenon of the transmission spectrums according to the effect
of which-way detection. The quantum realization of the present model is a
nano-electromechanical resonator arrays with two nearest resonators coupled to
a single spin via their attached magnetic tips. Its classical simulation is a
waveguide of coupled defected cavity array with double couplings to a side
defected cavity.Comment: 5 papges, 4 figure
Quantum dynamics of topological strings in a frustrated Ising antiferromagnet
We investigate the quantum dynamics of the transverse field Ising model on
the triangular lattice through large-scale quantum Monte Carlo simulations and
stochastic analytic continuation. At weak transverse field, we capture for the
first time the excitations related to topological quantum strings, which
exhibits continuum features described by XY chain along the strings and those
in accord with "Luttinger string liquid" in the perpendicular direction. The
continuum features can be well understood from the perspective of topological
strings. Furthermore, we identify the contribution of strings from the
excitation spectrum. Our study provides characteristic features for the
experimental search for string-related excitations and proposes a new
theoretical method to pinpoint topological excitations in the experimental
spectra.Comment: 10 pages, 9 figures, comments are welcome and more information at
http://cqutp.org/users/xfzhang
The Genus Prosopistoma from China, with Descriptions of Two New Species (Ephemeroptera: Prosopistomatidae)
Abstract Two mayfly species Prosopistoma trispinum sp.n. and P. unicolor sp.n. collected from southwestern China are described as new to science, their main diagnostic larval characters are illustrated. The larvae of P. trispinum sp. n. can be differentiated by the large number of mandibular bristles, fewer spines on the inner margins of fore tibiae and mesonotal color pattern. The larva of P. unicolor sp. n. can be distinguished by its uniform reddish brown mesothoracic carapace which has no median ridge, and by more tiny serrated foretibial bristles. New distributional records for P. annamense Soldán et Braasch in China are first provided. The habitats of Chinese Prosopistomatidae show they can live in lotic water from stream to large river
and
Recently Babar Collaboration reported a new state
and Belle Collaboration observed . We investigate the strong
decays of the excited states using the model. After
comparing the theoretical decay widths and decay patterns with the available
experimental data, we tend to conclude: (1) is probably the
state although the
assignment is not completely excluded; (2) seems unlikely to be
the and candidate; (3)
as either a or state is
consistent with the experimental data; (4) experimental search of
in the channels , , and
will be crucial to distinguish the above two possibilities.Comment: 18 pages, 7 figures, 2 tables. Some discussions added. The final
version to appear at EPJ
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Water-Soluble Flexible Organic Frameworks That Include and Deliver Proteins.
Four water-soluble hydrazone-based three-dimensional (3D) flexible organic frameworks FOF-1-4 have been synthesized from a semirigid tetracationic tetraaldehyde and four flexible dihydrazides. 1H NMR spectroscopy indicated the quantitative formation of FOF-1-4 in D2O, while dynamic light scattering experiments revealed that, depending on the concentration, these porous frameworks display hydrodynamic diameters ranging from 50 to 120 nm. The porosity of the frameworks is confirmed by ethanol vapor adsorption experiments of the solid samples as well as the high loading capacity for a 2.3 nm porphyrin guest in water. The new water-soluble frameworks exhibit low cytotoxicity and form inherent pores with diameters of 5.3 or 6.7 nm, allowing rapid inclusion of proteins such as bovine serum albumin and green and orange fluorescent proteins, and efficient delivery of the proteins into normal and cancer cells. Flow cytometric analysis reveals percentages of the delivered cells up to 99.8%
21 cm foreground removal using AI and frequency-difference technique
The deep learning technique has been employed in removing foreground
contaminants from 21 cm intensity mapping, but its effectiveness is limited by
the large dynamic range of the foreground amplitude. In this study, we develop
a novel foreground removal technique grounded in U-Net networks. The essence of
this technique lies in introducing an innovative data preprocessing step
specifically, utilizing the temperature difference between neighboring
frequency bands as input, which can substantially reduce the dynamic range of
foreground amplitudes by approximately two orders of magnitude. This reduction
proves to be highly advantageous for the U-Net foreground removal. We observe
that the HI signal can be reliably recovered, as indicated by the
cross-correlation power spectra showing unity agreement at the scale of Mpc in the absence of instrumental effects. Moreover, accounting for
the systematic beam effects, our reconstruction displays consistent
auto-correlation and cross-correlation power spectrum ratios at the
level across scales Mpc, with only a 10% reduction
observed in the cross-correlation power spectrum at Mpc. The
effects of redshift-space distortion are also reconstructed successfully, as
evidenced by the quadrupole power spectra matching. In comparison, our method
outperforms the traditional Principal Component Analysis method, which derived
cross-correlation ratios are underestimated by around 75%. We simulated various
white noise levels in the map and found that the mean cross-correlation ratio
when the level of the thermal noise is
smaller than or equal to that of the HI signal. We conclude that the proposed
frequency-difference technique can significantly enhance network performance by
reducing the amplitude range of foregrounds and aiding in the prevention of HI
loss.Comment: 18 pages, 16 figure
Nonequilibrium probe of paired electron pockets in the underdoped cuprates
We propose an experimental method that can be used generally to test whether
the cuprate pseudogap involves precursor pairing that acts to gap out the Fermi
surface. The proposal involves angular-resolved photoemission spectroscopy
(ARPES) performed in the presence of a transport current driven through the
sample. We illustrate this proposal with a specific model of the pseudogap that
contains a phase-incoherent paired electron and unpaired hole Fermi surfaces.
We show that even a weak current tilts the paired band and reveals parts of the
previously gapped electron Fermi surface in ARPES if the binding energy is
smaller but close to the pseudogap. Stronger currents can also reveal the Fermi
surface through direct suppression of pairing. The proposed experiment is
sufficiently general such that it can be used to reveal putative Fermi surfaces
that have been reconstructed from other types of periodic order and are gapped
out due to pairing. The observation of the predicted phenomena should help
resolve the central question about the existence of pairs in the enigmatic
pseudogap regime.Comment: 5 pages, 3 figures (published version
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