19 research outputs found
Quantum interference and controllable magic cavity QED via giant atom in coupled resonator waveguide
We study the Markovian and Non-Markovian dynamics in a giant atom system
which couples to a coupled resonator waveguide (CRW) via two distant sites.
Under certain conditions, we find that the giant atom population can exhibit an
oscillating behavior and the photon can be trapped in the giant atom regime.
These phenomena are induced by the interference effect among the bound states
both in and outside the continuum. As an application of the photon trapping, we
theoretically propose a magic cavity model where the giant atom serve as either
a perfect or leaky cavity, depending on the distance between the coupling
sites. The controllability of the magic cavity from perfect to leaky one can
not be realized in the traditional cavity or circuit QED setup. The predicted
effects can be probed in state-of-the-art waveguide QED experiments and provide
a striking example of how the different kinds of bound states modify the
dynamics of quantum open system in a structured environment.Comment: 11 pages, 7 figures, comments are welcome
Anomalously Robust Valley Polarization and Valley Coherence in Bilayer WS2
Coherence is a crucial requirement to realize quantum manipulation through
light-matter interactions. Here we report the observation of anomalously robust
valley polarization and valley coherence in bilayer WS2. The polarization of
the photoluminescence from bilayer WS2 inherits that of the excitation source
with both circularly and linearly polarized and retains even at room
temperature. The near unity circular polarization of the luminescence reveals
the coupling of spin, layer and valley degree of freedom in bilayer system,
while the linear polarized photoluminescence manifests quantum coherence
between the two inequivalent band extrema in momentum space, namely, the valley
quantum coherence in atomically thin bilayer WS2. This observation opens new
perspectives for quantum manipulation in atomically thin semiconductors
Ancient Genomes Reveal the Evolutionary History and Origin of Cashmere-Producing Goats in China
Goats are one of the most widespread farmed animals across the world; however, their migration route to East Asia and local evolutionary history remain poorly understood. Here, we sequenced 27 ancient Chinese goat genomes dating from the Late Neolithic period to the Iron Age. We found close genetic affinities between ancient and modern Chinese goats, demonstrating their genetic continuity. We found that Chinese goats originated from the eastern regions around the Fertile Crescent, and we estimated that the ancestors of Chinese goats diverged from this population in the Chalcolithic period. Modern Chinese goats were divided into a northern and a southern group, coinciding with the most prominent climatic division in China, and two genes related to hair follicle development, FGF5 and EDA2R, were highly divergent between these populations. We identified a likely causal de novo deletion near FGF5 in northern Chinese goats that increased to high frequency over time, whereas EDA2R harbored standing variation dating to the Neolithic. Our findings add to our understanding of the genetic composition and local evolutionary process of Chinese goats
Magnetic Control of Valley Pseudospin in Monolayer WSe2
Local energy extrema of the bands in momentum space, or valleys, can endow
electrons in solids with pseudo-spin in addition to real spin. In transition
metal dichalcogenides this valley pseudo-spin, like real spin, is associated
with a magnetic moment which underlies the valley-dependent circular dichroism
that allows optical generation of valley polarization, intervalley quantum
coherence, and the valley Hall effect. However, magnetic manipulation of valley
pseudospin via this magnetic moment, analogous to what is possible with real
spin, has not been shown before. Here we report observation of the valley
Zeeman splitting and magnetic tuning of polarization and coherence of the
excitonic valley pseudospin, by performing polarization-resolved
magneto-photoluminescence on monolayer WSe2. Our measurements reveal both the
atomic orbital and lattice contributions to the valley orbital magnetic moment;
demonstrate the deviation of the band edges in the valleys from an exact
massive Dirac fermion model; and reveal a striking difference between the
magnetic responses of neutral and charged valley excitons which is explained by
renormalization of the excitonic spectrum due to strong exchange interactions
Tranexamic acid reduces intraoperative occult blood loss and tourniquet time in obese knee osteoarthritis patients undergoing total knee arthroplasty: a prospective cohort study
LncRNA NR_003508 Suppresses <i>Mycobacterium tuberculosis</i>-Induced Programmed Necrosis via Sponging miR-346-3p to Regulate RIPK1
Emerging evidence suggests that long non-coding RNAs (LncRNAs) are involved in Mtb-induced programmed necrosis. Among these LncRNAs, LncRNA NR_003508 is associated with LPS-induced acute respiratory distress syndrome. However, whether LncRNA NR_003508 contributes to Mtb-induced programmed necrosis remains undocumented. Firstly, the expression of LncRNA NR_003508 was determined using RT-qPCR and FISH. The protein expression of RIPK1, p-RIPK1, RIPK3, p-RIPK3, MLKL, and p-MLKL was measured by Western blot in RAW264.7 and mouse lung tissues. Furthermore, luciferase reporter assays and bioinformatics were used to predict specific miRNA (miR-346-3p) and mRNA (RIPK1) regulated by LncRNA NR_003508. In addition, RT-qPCR was used to detect the RIPK1 expression in TB patients and healthy peripheral blood. The flow cytometry assay was performed to detect cell necrosis rates. Here we show that BCG infection-induced cell necrosis and increased LncRNA NR_003508 expression. si-NR_003508 inhibited BCG/H37Rv-induced programmed necrosis in vitro or in vivo. Functionally, LncRNA NR_003508 has been verified as a ceRNA for absorbing miR-346-3p, which targets RIPK1. Moreover, RIPK1 expression was elevated in the peripheral blood of TB patients compared with healthy people. Knockdown of LncRNA NR_003508 or miR-346-3p overexpression suppresses cell necrosis rate and ROS accumulation in RAW264.7 cells. In conclusion, LncRNA NR_003508 functions as a positive regulator of Mtb-induced programmed necrosis via sponging miR-346-3p to regulate RIPK1. Our findings may provide a promising therapeutic target for tuberculosis