Overcoming noise in quantum teleportation with multipartite hybrid entanglement.

Quantum entanglement and decoherence are the two counterforces of many quantum technologies and protocols. For example, while quantum teleportation is fueled by a pair of maximally entangled resource qubits, it is vulnerable to decoherence. Here, we propose an efficient quantum teleportation protocol in the presence of pure decoherence and without entangled resource qubits entering the Bell-state measurement. Instead, we use multipartite hybrid entanglement between the auxiliary qubits and their local environments within the open-quantum system context. With a hybrid-entangled initial state, it is the decoherence that allows us to achieve high fidelities. We demonstrate our protocol in an all-optical experiment.

Robust coherent control of solid-state spin qubits using anti-Stokes excitation.

Optically addressable solid-state color center spin qubits have become important platforms for quantum information processing, quantum networks and quantum sensing. The readout of color center spin states with optically detected magnetic resonance (ODMR) technology is traditionally based on Stokes excitation, where the energy of the exciting laser is higher than that of the emission photons. Here, we investigate an unconventional approach using anti-Stokes excitation to detect the ODMR signal of silicon vacancy defect spin in silicon carbide, where the exciting laser has lower energy than the emitted photons. Laser power, microwave power and temperature dependence of the anti-Stokes excited ODMR are systematically studied, in which the behavior of ODMR contrast and linewidth is shown to be similar to that of Stokes excitation. However, the ODMR contrast is several times that of the Stokes excitation. Coherent control of silicon vacancy spin under anti-Stokes excitation is then realized at room temperature. The spin coherence properties are the same as those of Stokes excitation, but with a signal contrast that is around three times greater. To illustrate the enhanced spin readout contrast under anti-Stokes excitation, we also provide a theoretical model. The experiments demonstrate that the current anti-Stokes excitation ODMR approach has promising applications in quantum information processing and quantum sensing.

A Photoluminescent Cd(II) Coordination Polymer with Potential Active Sites Exhibiting Multiresponsive Fluorescence Sensing for Trace Amounts of NACs and Fe3+ and Al3+ Ions.

The elaborately designed π-electron-rich fluorescent ligand 1,4-bis(1-carboxymethylene-4-imidazolyl)benzene (H2L), possessing bifunctional groups including the carboxylate groups (building units) and 4-imidazoyl groups (N-donor potential active sites) has been employed to construct fluorescent coordination polymers. A luminescent sensor, namely [Cd(L)(phen)2]·5H2O (1), was obtained, which has a one-dimensional structure. The fluorescent material shows a blue emission maximum at 457 nm with a luminescence lifetime of 488 ns and a quantum yield (QY) of 4.56%. Significantly, 1 serves as a promising multiresponsive luminescent sensor to detect trace nitroaromatic compounds (NACs) with the limits of detection (LOD) of 7.21 × 10-8, 1.85 × 10-5, and 1.15 × 10-5 mol/L for 2-nitrophenol (2-NP), 3-nitrophenol (3-NP), and 4-nitrophenol (4-NP), respectively. Furthermore, CP 1 exhibits fluorescent turn-off and turn-on sensing behavior for Fe3+ and Al3+ metal ions with trace amounts of 1.05 × 10-7 and 1.13 × 10-7 mol/L, respectively. Experimental methods and theoretical calculations were employed to elucidate the sensing mechanism in detail.

Achieving Heisenberg-Scaling Precision with Projective Measurement on Single Photons.

It has been suggested that both quantum superpositions and nonlinear interactions are important resources for quantum metrology. However, to date the different roles that these two resources play in the precision enhancement are not well understood. Here, we experimentally demonstrate a Heisenberg-scaling metrology to measure the parameter governing the nonlinear coupling between two different optical modes. The intense mode with n (more than 10^{6} in our work) photons manifests its effect through the nonlinear interaction strength which is proportional to its average photon number. The superposition state of the weak mode, which contains only a single photon, is responsible for both the linear Hamiltonian and the scaling of the measurement precision. By properly preparing the initial state of single photon and making projective photon-counting measurements, the extracted classical Fisher information (FI) can saturate the quantum FI embedded in the combined state after coupling, which is ∼n^{2} and leads to a practical precision ≃1.2/n. Free from the utilization of entanglement, our work paves a way to realize Heisenberg-scaling precision when only a linear Hamiltonian is involved.

Experimental implementation of fully controlled dephasing dynamics and synthetic spectral densities.

Engineering, controlling, and simulating quantum dynamics is a strenuous task. However, these techniques are crucial to develop quantum technologies, preserve quantum properties, and engineer decoherence. Earlier results have demonstrated reservoir engineering, construction of a quantum simulator for Markovian open systems, and controlled transition from Markovian to non-Markovian regime. Dephasing is an ubiquitous mechanism to degrade the performance of quantum computers. However, all-purpose quantum simulator for generic dephasing is still missing. Here, we demonstrate full experimental control of dephasing allowing us to implement arbitrary decoherence dynamics of a qubit. As examples, we use a photon to simulate the dynamics of a qubit coupled to an Ising chain in a transverse field and also demonstrate a simulation of nonpositive dynamical map. Our platform opens the possibility to simulate dephasing of any physical system and study fundamental questions on open quantum systems.

Preliminary application of multiple parameters spectral CT in the diagnosis of ovarian cancer.

The aim of the study was to evaluate the effectiveness of spectral CT in the diagnosis of ovarian cancer. We retrospectively analyzed the data of 22 patients with spectral CT enhanced scan. The patients were divided into 2 groups: ovarian cancer group (n = 11) and benign tumor group (n = 11), according to the pathologic results. CT values at 40 keV, iodine concentration (IC), water concentration (WC) and spectral curve slope (λHU) of arterial phase and venous phase in the tumors of 2 groups were measured with gemstone spectral imaging (GSI) post-processing software. The independent samples t test was used to compare these multiple parameters above between 2 groups. For the parameters which showed statistically different, the ROC curves were further generated to calculate their diagnostic effectiveness respectively. According to the results, CT values at 40 keV, IC and λHU measured in arterial and venous phases were higher in ovarian cancer group than those in benign tumor group. There were significant differences between these 2 groups (P < 0.05). While WC had no significant difference in these 2 groups (P > 0.05). CT values at 40 keV, IC and λHU had high effectiveness to the diagnosis of ovarian cancer according to ROC curves. The optimal parameter among them was IC in arterial phase with AUC of 0.90. Using 10.92 (100 ug/cm3) as a threshold value, the sensitivity and specificity for diagnosis were 88.9% and 94.7%. Thus, we concluded that spectral CT with multiple parameters was valuable in the diagnosis of ovarian cancer.

Degenerate cavity supporting more than 31 Laguerre-Gaussian modes.

Photons propagating in Laguerre-Gaussian modes have characteristic orbital angular momenta, which are fundamental optical degrees of freedom. The orbital angular momentum of light has potential application in high-capacity optical communication and even in quantum information processing. In this work, we experimentally construct a ring cavity with four lenses and four mirrors that is completely degenerate for Laguerre-Gaussian modes. By measuring the transmitted peaks and patterns of different modes, the ring cavity is shown to support more than 31 Laguerre-Gaussian modes. The constructed degenerate cavity opens a new way for using the unlimited resource of available angular momentum states simultaneously.

Determination of nitrofuran metabolites in shrimp by high performance liquid chromatography with fluorescence detection and liquid chromatography-tandem mass spectrometry using a new derivatization reagent.

A high performance liquid chromatography with fluorescence detection (HPLC-FLD) method for the simultaneous determination of total nitrofuran metabolite residues (furazolidone, furaltadone, nitrofurantoin, and nitrofurazone) in shrimp was developed. The method involves the acid hydrolysis of protein-bound metabolites, followed by the derivatization of the freed metabolites with the new fluorescent derivatization reagent 2-hydroxy-1-naphthaldehyde (HN) and subsequent liquid-liquid extraction (LLE). Separation is achieved on a YMC-Pack Polymer C18 column under alkaline conditions, and the high fluorescence intensity of the derivatives at an emission wavelength Em=463nm (Ex=395nm) enables, for the first time, their simultaneous determination in shrimp at concentrations as low as 1µg/kg by HPLC-FLD. The method was validated using blank shrimp fortified with all four metabolites at 0.5, 1.0 and 2.0µg/kg. Recoveries were >87% with relative standard deviations of <8.1% for all four metabolites. Furthermore, the results obtained by HPLC-FLD were in very good agreement with those obtained by LC-MS/MS analysis.

High-performance liquid chromatography with fluorescence detection for the determination of nitrofuran metabolites in pork muscle.

A simple and sensitive HPLC method with fluorescence detection (HPLC-FLD) is reported for the simultaneous determination of metabolites of four nitrofuran drugs (furazolidone, furaltadone, nitrofurantoin and nitrofurazone) in pork muscle. The method involves acid hydrolysis of the protein-bound drug metabolites and the conjugation of the released side-chains with a novel fluorescence agent 2-hydroxy-1-naphthaldehyde. After liquid-liquid extraction and effective separation of the derivatives on a YMC-Pack Polymer C18 column at 40°C under alkaline conditions, the high fluorescence intensity of these derivatives at emission wavelength λem = 463 nm enables their simultaneous determination in pork muscle at concentrations as low as 1 µg kg⁻¹. The method was validated using blank pork muscle fortified with all four metabolites at 0.5, 1.0 and 2.0 µg kg⁻¹. Recoveries were > 92.3% with RSDs < 8.5% for all four metabolites. The results obtained with HPLC-FLD and LC-MS/MS methods showed very good agreement for pork muscle samples.

N,N-Di-phenyl-4-(1H-pyrrolo[1,2-f][1,10]phenanthro-lin-2-yl)-aniline ethanol monosolvate.

The title compound, C32H21N4·C2H5OH, crystallized as an ethanol monosolvate. In the mol-ecule of this phenanthroline derivative, the pyridine rings are almost coplanar, making a dihedral angle of 1.54 (13)°. The tri-phenyl-amine group, introduced as an electron donor, shows a propeller-type structure, and the dihedral angles between the benzene rings are 68.71 11), 63.92 (16) and 70.81 (15)°. In the crystal, the phenanthroline mol-ecules are linked via the solvent mol-ecule by N-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds, leading to the formation of zigzag chains propagating along [010]. These chains are linked via C-H⋯N hydrogen bonds, forming undulating two-dimensional networks extending in the a- and b-axis directions.

2-[(E)-(2-Hy-droxy-naphthalen-1-yl)methyl-idene-amino]-isoindoline-1,3-dione.

The title compound, C(19)H(12)N(2)O(3), has two independent mol-ecules (A and B) in the asymmetric unit. There is an intra-molecular O-H⋯N hydrogen bond in each mol-ecule. The mean planes of the naphthalene [maximum deviations = 0.024 (3) and 0.030 (3) Šin A and B, respectively] and the isoindoline units [maximum deviations 0.009 (3) and 0.008 (3) Šin A and B, respectively] are almostly coplanar, with dihedral angles of 4.25 (9) ad 3.84 (9)° in mol-ecules A and B, respectively. The two independent mol-ecules are connected by π-π inter-actions [centroid-centroid distances 3.5527 (19) and 3.5627 (19) Å]. In the crystal, the A+B pairs are further connected via π-π inter-actions [centroid-centroid distances = 3.693 (2)-3.831 (2) Å], leading to the formation of columns propagating along the a-axis direction. The columns are linked via C-H⋯O inter-actions, leading to the formation of a three-dimensional network.

(E)-2-[(2-Chloro-benzyl-idene)amino]-isoindoline-1,3-dione.

The title compound, C(15)H(9)ClN(2)O(2), adopts an E configuration about the C=N double bond. The mean plane of the isoindoline ring system [maximum deviation = 0.011 (2) Å] is inclined to the chloro-benzene ring by 22.62 (8)°. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds, forming chains that propagate along [010].

10-Ethyl-10H-phenothia-zine-3-carbaldehyde.

In the title mol-ecule, C(15)H(13)NOS, the two benzene rings of the tricyclic fused-ring system are inclined at 21.1 (1)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains along [001]. The crystal packing also exhibits π-π inter-actions with a distance of 3.801 (5) Šbetween the centroids of the benzene rings of neighbouring mol-ecules.

Synthesis, crystal structure, electrochemistry and in situ FTIR spectroelectrochemistry of a bisferrocene pyrazole derivative.

One novel bisferrocene pyrazole derivative, bis [2-(5-trifluoromethyl-3-ferrocenyl) pyrazolyl] methane (abbreviated as (3)), was synthesized and fully characterized. A single crystal of (3) was obtained and solved by X-ray diffraction analysis. The bisferrocene derivative exhibits MLCT (metal to ligand charge transfer) and π→π* transitions in the UV-visible range, which have been verified by density functional theory (DFT) calculations. Its electrochemical properties were studied with the aid of cyclic voltammetry (CV), differential pulse voltammetry (DPV) and rapid scan time-resolved Fourier transform infrared spectroscopy (RS-TRS FT-IR) analysis. Furthermore, the electrochemical mechanism was elucidated based on the results from the cyclic voltabsorptometry (CVA) determination technique. (3) apparently shows a single wave in the cyclic voltammetric experiments which indicates there is no intermediate, however, the intermediate of (3) was observed by employing the RS-TRS FT-IR spectroelectrochemistry technique. The detailed investigation brought us safely to the conclusion that the methylene can also act as a linker, leading to electronic communication in either D-π-D and A-π-A systems.

2,2'-[(1E,1'E)-2,2'-(2,5-Dibut-oxy-1,4-phenyl-ene)bis-(ethene-2,1-di-yl)]dipyridine.

The centrosymmetric title mol-ecule, C(28)H(32)N(2)O(2), has a central benzene ring subsituted in the 1- and 4-positions by (ethene-2,1-di-yl)pyridine groups, and in the 2- and 5-positions by but-oxy groups. The whole mol-ecule is X-shaped and relatively flat, the dihedral angle between the pyridine and the central benzene ring being 11.29 (10)°. In the crystal, neighboring mol-ecules are linked by weak C-H⋯N inter-actions, forming a two-dimensional undulating network.

Redetermination of tris-(N,N-diethyl-dithio-carbamato)anti-mony(III).

The title compound, [Sb(C(5)H(10)NS(2))(3)], was synthesized from Sb(2)O(3), diethyl-amine, carbon dis-ulfide, hydro-chloric acid and sodium hydroxide. The structure has been published previously but H atoms were not included in the model [Raston & White (1976 ▶). Chem. Soc. Dalton Trans. p. 791]. The current determination has significantly higher precision than the original work. The complex has three ligands. The Sb atom is coordinated by three bidentate diethyl-dithio-carbamate groups, two in an almost planar fashion and the third perpendicular to that plane with a dihedral angle of 86.429 (13)°. One ethyl group is disordered over two positions of equal occupancy.

(E)-N'-(3-Fluoro-benzyl-idene)-2-hydroxy-benzohydrazide.

The title compound, C(14)H(11)FN(2)O(2), adopts an E or trans configuration with respect to the C=N bond. An intra-molecular N-H⋯O hydrogen bond contributes to the relatively planarity of the mol-ecular conformation; the two benzene rings are inclined to one another by 12.5 (2)°. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into chains running parallel to the c axis.

2-[4-(4-Methoxy-phen-yl)-5-(2-pyrid-yl)-4H-1,2,4-triazol-3-yl]phenol.

In the title compound, C(20)H(16)N(4)O(2), the benzene rings of the 2-hydroxy-phenyl and 4-methoxy-lphenyl groups form dihedral angles of 64.02 (8) and 77.39 (7)°, respectively, with the mean plane of the triazole ring. The dihedral angle between the triazole ring mean plane and the pyridyl ring is 9.61 (8)°. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains propagating in [010].

catena-Poly[1,4-diazoniabicyclo[2.2.2]octane [silver(I)-tri-mu-thiocyanato-kappa6S:S]].

The title compound, [(C6H14N2)[Ag(NCS)3]]n, is a polymeric silver(I) complex. The Ag(I) atom is hexacoordinated by the S atoms of six thiocyanate anions, with each thiocyanate S atom acting in a bridging mode to link the Ag atoms together. The unique Ag(I) atom lies at a cell origin and has crystallographically imposed 3 symmetry. The diazonia[2.2.2]octane molecule lies about a site with 6 imposed symmetry with the unique N atom on a threefold axis. The S and N atoms of the thiocyanate ligands sit on a mirror plane and a threefold axis, respectively. The crystal structure consists of one-dimensional chains, which are stabilized by N-H...N hydrogen bonds to form a three-dimensional network.