Magic wavelengths for the 6s^2\,^1S_0-6s6p\,^3P_1^o transition in ytterbium atom

The static and dynamic electric-dipole polarizabilities of the 6s^2\,^1S_0 and 6s6p\,^3P_1^o states of Yb are calculated by using the relativistic ab initio method. Focusing on the red detuning region to the 6s^2\,^1S_0-6s6p\,^3P_1^o transition, we find two magic wavelengths at 1035.7(2) nm and 612.9(2) nm for the 6s^2\,^1S_0-6s6p\,^3P_1^o, M_J=0 transition and three magic wavelengthes at 1517.68(6) nm, 1036.0(3) nm and 858(12) nm for the 6s^2\,^1S_0-6s6p\,^3P_1^o, M_J=\pm1 transitions. Such magic wavelengths are of particular interest for attaining the state-insensitive cooling, trapping, and quantum manipulation of neutral Yb atom.Comment: 13 pages, 3 figure

Robust Spin Squeezing Preservation in Photonic Crystal Cavities

We show that the robust spin squeezing preservation can be achieved by utilizing detuning modification for an ensemble of N separate two-level atoms embedded in photonic crystal cavities (PCC). In particular, we explore the different dynamical behaviors of spin squeezing between isotropic and anisotropic PCC cases when the atomic frequency is inside the band gap. In both cases, it is shown that the robust preservation of spin squeezing is completely determined by the formation of bound states. Intriguingly, we find that unlike the isotropic case where steady-state spin squeezing varies smoothly when the atomic frequency moves from the inside to the outside band edge, a sudden transition occurs for the anisotropic case. The present results may be of direct importance for, e.g., quantum metrology in open quantum systems.Comment: 6 pages, 4 figures, accepted by Laser Physics Letter

Research Progress and Trend of School Sport Psychology

The Outline of Healthy China 2030 Plan clearly proposed to develop youth and adolescent physical health intervention plan. School physical education/sports not only plays a major role in promoting a physically active lifestyle among school students, it can also make a significant contribution to the Healthy China 2030 Plan. Previous research has indicated school sport psychology as an important area to provide quality physical education programs. The purpose of this study, therefore, was to examine the research progress and trend of school sport psychology to inform future research practice and identify effective strategies for physical activity participation. All relevant literature on school physical education psychology from 2000 to 2021 were collected from CNKI and WOS databases, a total of 4347 papers were collected. To ensure the accuracy of the research, the inconsistent literature was manually eliminated, and 1642 effective journal papers were finally selected. CiteSpace 5.7.R4 software was used for scientific measurement and visualization analysis. The results suggest that the studies conducted in China mainly focus on higher education with college students as related to exercise/physical activity and mental health, while other countries attempt to develop exploration, validation, and intervention studies among children and adolescents to promote physical activity from psychological perspectives. The results also indicates that interdisciplinary research with sophisticated methodology has become popular in the field of school sport psychology. Meanwhile, the research focuses on the application function, physical education practice, and other aspects. The research frontier mainly manifested in “academic,” “performance,” “psychological capital,” “regression analysis,” “mediating effect,” “Physical Education of Fit Index,” “Intervention,” and related research. Research studies guided by the theoretical frameworks of psychology in physical education have revealed the relationship between psychological constructs and student learning as well as physical activity participation. The results have built a solid foundation for future research. Intervention studies can be conducted from different aspects using effective strategies identified in previous research. To better understand student adaptive behavior with respect to learning and physical activity, a mixed method research design is also recommended for future studies

Enhancing teleportation of quantum Fisher information by partial measurements

The purport of quantum teleportation is to completely transfer information from one party to another distant partner. However, from the perspective of parameter estimation, it is the information carried by a particular parameter, not the information of total quantum state that needs to be teleported. Due to the inevitable noise in environment, we propose two schemes to enhance quantum Fisher information (QFI) teleportation under amplitude damping noise with the technique of partial measurements. We find that post partial measurement can greatly enhance the teleported QFI, while the combination of prior partial measurement and post partial measurement reversal could completely eliminate the effect of decoherence. We show that, somewhat consequentially, enhancing QFI teleportation is more economic than that of improving fidelity teleportation. Our work extends the ability of partial measurements as a quantum technique to battle decoherence in quantum information processing.Comment: Revised version, minor changes, accepted by Phys. Rev.

Bis[N,N-bis­(2-hydroxy­ethyl)dithio­carbamato-κ2 S,S′]copper(II)

In the title compound, [Cu(C5H10NO2S2)2], the CuII cation is chelated by two bis­(2-hydroxy­ethyl)dithio­carbamate anions with a distorted square-planar coordination geometry. Inter­molecular O—H⋯O hydrogen bonding is observed between the terminal hydr­oxy groups in the crystal structure

Methyl 4-methyl­sulfonyl-2-nitro­benzoate

The title compound, C9H9NO6S, was prepared by the reaction of methanol and thionyl chloride with 4-methyl­sulfonyl-2-nitro­benzoic acid under mild conditions. The dihedral angle between the nitro group and benzene ring is 21.33 (19)° and that between the carboxyl­ate group and the benzene ring is 72.09 (17)°. The crystal structure is stabilized by weak inter­molecular bifurcated C—H⋯O inter­actions occurring in the (100) plane

Ethyl N-[3-(N,N-dimethyl­carbamo­yl)pyridin-2-ylsulfon­yl]carbamate

In the mol­ecular structure of the title compound, C11H15N3O5S, the amide group is nearly perpendicular to the pyridine ring, making a dihedral angle of 86.30 (13)°. The terminal ethyl group is disordered over two sites of equal occupancy. Inter­molecular N—H⋯O hydrogen bonding is present in the crystal structure

Molecular Insights into Cage Occupancy of Hydrogen Hydrate: A Computational Study

Density functional theory calculations and molecular dynamics simulations were performed to investigate the hydrogen storage capacity in the sII hydrate. Calculation results show that the optimum hydrogen storage capacity is ~5.6 wt%, with the double occupancy in the small cage and quintuple occupancy in the large cage. Molecular dynamics simulations indicate that these multiple occupied hydrogen hydrates can occur at mild conditions, and their stability will be further enhanced by increasing the pressure or decreasing the temperature. Our work highlights that the hydrate is a promising material for storing hydrogen