Quasinormal modes of warped AdS3AdS_3 black holes and AdS/CFT correspondence

We calculate the scalar quasinormal modes of warped $AdS_3$ black holes analytically. We find that in general they are not in agreement with the prediction of the usual AdS/CFT correspondence. Nevertheless, for the black hole not deviating far from BTZ black hole, the quasinormal frequencies are still well consistent with AdS/CFT correspondence.Comment: 10 pages; more clarifications, references adde

Efficient infrared upconversion via a ladder-type atomic configuration

We have demonstrated experimentally that infrared light at 1529.4nm can be converted into the visible at 780nm with 54% efficiency through a ladder-type atomic configuration in 85Rb. Specifically we theoretically analyze that high efficiency is due to the large nonlinear dispersion of the index of refraction from the off-resonant enhancement in a four-wave mixing (FWM) process. By using two perpendicular polarized pump fields, the coherence of two FWM processes in this configuration is verified.Comment: The new version is published in Journal of Modern Optic

Poly[diaqua­(μ-oxalato)(μ-2-oxidopyridinium-3-carboxyl­ato)lanthanum(III)]

In the title complex, [La(C6H4NO3)(C2O4)(H2O)2]n, the LaIII ion is coordinated by eight O atoms from two 2-oxido­pyridinium-3-carboxyl­ate ligands, two oxalate ligands and two water mol­ecules in a distorted bicapped square-anti­prismatic geometry. The carboxyl­ate groups link adjacent LaIII ions, forming two-dimensional layers that are further linked by N—H⋯O and O—H⋯O hydrogen bonds

Chemical composition and insecticidal properties of the essential oil of Bidens frondosa L (Asteraceae) against booklice (Liposcelis bostrychophila)

Purpose: To investigate contact and fumigant toxicity of the essential oil of Bidens frondosa and its isolated constituents against booklice (Liposcelis bostrychophila).Methods: The essential oil of B. frondosa was obtained by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) with HP-5MS column. The active constituents were purified from the oil by bioactivity-guided fractionation. Contact (impregnated filter paper method) and fumigant toxicity (sealed space) of the oil and its isolates were determined.Results: Thirty-two compounds, representing 98.88 % of the total oil, were determined and the major constituents of the essential oil were caryophyllene oxide (20.50 %), borneol (17.66 %), 4-terpineol (17.26 %), and β-cedrene (6.94 %). The essential oil displayed fumigant toxicity against booklice, with a median lethal concentration (LC50) of 507.35 μg/L while the isolated constituents, borneol and 4-terpineol, had LC50 values of 2.20 mg/L and 335.24 μg/L against booklice, respectively. The essential oil also exhibited contact toxicity against L. bostrychophila with an LC50 value of 210.73 μg/cm2. Borneol, caryophyllene oxide, β-cedrene, and 4-terpineol showed acute toxicity against booklice with LC50 of 98.04, 84.62, 458.79 and 211.35 μg/cm2, respectively.Conclusion: The results suggest that the essential oil and its isolates possess potential for cultivation into natural insecticides or fumigants, for control of insects in stored grains.Keywords: Bidens frondosa, Liposcelis bostrychophila, Contact toxicity, Essential oil, Boolice, Stored grains, Natural insecticides, Fumigant

Variational quantum simulation of the quantum critical regime

The quantum critical regime marks a zone in the phase diagram where quantum fluctuation around the critical point plays a significant role at finite temperatures. While it is of great physical interest, simulation of the quantum critical regime can be difficult on a classical computer due to its intrinsic complexity. In this paper, we propose a variational approach, which minimizes the variational free energy, to simulate and locate the quantum critical regime on a quantum computer. The variational quantum algorithm adopts an ansatz by performing an unitary operator on a product of a single-qubit mixed state, in which the entropy can be analytically obtained from the initial state, and thus the free energy can be accessed conveniently. With numeral simulation, we show, using the one-dimensional Kitaev model as a demonstration, the quantum critical regime can be identified by accurately evaluating the temperature crossover line. Moreover, the dependence of both the correlation length and the phase coherence time with the temperature are evaluated for the thermal states. Our work suggests a practical way as well as a first step for investigating quantum critical systems at finite temperatures on quantum devices with few qubits