29 research outputs found
Experimental Gaussian Boson Sampling
Gaussian Boson sampling (GBS) provides a highly efficient approach to make
use of squeezed states from parametric down-conversion to solve a classically
hard-to-solve sampling problem. The GBS protocol not only significantly
enhances the photon generation probability, compared to standard boson sampling
with single photon Fock states, but also links to potential applications such
as dense subgraph problems and molecular vibronic spectra. Here, we report the
first experimental demonstration of GBS using squeezed-state sources with
simultaneously high photon indistinguishability and collection efficiency. We
implement and validate 3-, 4- and 5-photon GBS with high sampling rates of 832
kHz, 163 kHz and 23 kHz, respectively, which is more than 4.4, 12.0, and 29.5
times faster than the previous experiments. Further, we observe a quantum
speed-up on a NP-hard optimization problem when comparing with simulated
thermal sampler and uniform sampler.Comment: 12 pages, 4 figures, published online on 2nd April 201
Surfactant-Modified CdS/CdCO<sub>3</sub> Composite Photocatalyst Morphology Enhances Visible-Light-Driven Cr(VI) Reduction Performance
The surfactant modification of catalyst morphology is considered as an effective method to improve photocatalytic performance. In this work, the visible-light-driven composite photocatalyst was obtained by growing CdS nanoparticles in the cubic crystal structure of CdCO3, which, after surfactant modification, led to the formation of CdCO3 elliptical spheres. This reasonable composite-structure-modification design effectively increased the specific surface area, fully exposing the catalytic-activity check point. Cd2+ from CdCO3 can enter the CdS crystal structure to generate lattice distortion and form hole traps, which productively promoted the separation and transfer of CdS photogenerated electron-hole pairs. The prepared 5-CdS/CdCO3@SDS exhibited excellent Cr(VI) photocatalytic activity with a reduction efficiency of 86.9% within 30 min, and the reduction rate was 0.0675 min−1, which was 15.57 and 14.46 times that of CdS and CdCO3, respectively. Finally, the main active substances during the reduction process, the photogenerated charge transfer pathways related to heterojunctions and the catalytic mechanism were proposed and analyzed
Phase-Programmable Gaussian Boson Sampling Using Stimulated Squeezed Light
The tantalizing promise of quantum computational speedup in solving certain
problems has been strongly supported by recent experimental evidence from a
high-fidelity 53-qubit superconducting processor1 and Gaussian boson sampling
(GBS) with up to 76 detected photons. Analogous to the increasingly
sophisticated Bell tests that continued to refute local hidden variable
theories, quantum computational advantage tests are expected to provide
increasingly compelling experimental evidence against the Extended
Church-Turing thesis. In this direction, continued competition between upgraded
quantum hardware and improved classical simulations is required. Here, we
report a new GBS experiment that produces up to 113 detection events out of a
144-mode photonic circuit. We develop a new high-brightness and scalable
quantum light source, exploring the idea of stimulated squeezed photons, which
has simultaneously near-unity purity and efficiency. This GBS is programmable
by tuning the phase of the input squeezed states. We demonstrate a new method
to efficiently validate the samples by inferring from computationally friendly
subsystems, which rules out hypotheses including distinguishable photons and
thermal states. We show that our noisy GBS experiment passes the
nonclassicality test using an inequality, and we reveal non-trivial genuine
high-order correlation in the GBS samples, which are evidence of robustness
against possible classical simulation schemes. The photonic quantum computer,
Jiuzhang 2.0, yields a Hilbert space dimension up to , and a sampling
rate faster than using brute-force simulation on supercomputers.Comment: 23 pages, 6 figures. Comments are welcom
BML-111 Protected LPS/D-GalN-Induced Acute Liver Injury in Rats
Lipoxins (LXs) display unique pro-resolving and anti-inflammatory functions in a variety of inflammatory conditions. The present study was undertaken to investigate the effects of BML-111 (5(S),6(R),7-trihydroxyheptanoic acid methyl ester), the agonist of lipoxin A4 receptor, in a model of Lipopolysaccharides (LPS) and d-Galactosamine (d-GalN) induced acute liver injury, and to explore the mechanisms. Histopathological analyses were carried out to quantify liver injury degree. The activities of myeloperoxidase (MPO) were examined to evaluate the levels of neutrophil infiltration. The activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum were detected to evaluate the functions of the liver. The amounts of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and interleukin-1β (IL-1β) were measured using enzyme-linked immunosorbent assay (ELISA), and the expression levels of transforming growth factor-β1(TGF-β1) and cyclooxygenase-2 (COX-2) were examined using Western blotting. The antioxidant capacity, the activities of inducible nitric oxide synthase (iNOS), the contents of malondialdehyde (MDA) and nitric oxide (NO) were analyzed with the kits via biochemical analysis. We established the model of acute liver injury with lipopolysaccharide and d-Galactosamine (LPS/d-GalN): (1) histopathological results and MPO activities, with the activities of AST and ALT in serum, consistently demonstrated LPS and d-GalN challenge could cause severe liver damage, but BML-111 could prevent pathological changes, inhibit neutrophil infiltration, and improve the hepatic function; (2) LPS/d-GalN increased TNF-α, IL-1β, COX-2, and IL-10, while decreasing TGF-β1. However, BML-111 could repress LPS/d-GalN -induced TNF-α, IL-1β and COX-2, meanwhile increasing the expression levels of TGF-β1 and IL-10; (3) LPS/d-GalN inhibited the activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and hydroxyl radical-scavenging ability, simultaneously increasing the levels of MDA and NO, so also the activity of iNOS. Otherwise, BML-111 could reverse all the phenomena. In a word, BML-111 played a protective role in acute liver injury induced by LPS and d-GalN in rats, through improving antioxidant capacity and regulating the balance of inflammatory cytokines