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Abstract: The evolution of Bose–Einstein condensates (BECs) loaded into a periodic ring optical lattices (OL) trap is studied. By means of the variational method and direct numerical simulations of the Gross–Pitaevskii (GP) equation, the ground state properties and the vortex stabilities of the condensates for both repulsive and attractive cases are investigated. The results show that the bound states exist for determinate OL strength and interatomic interaction. However, the ground states of BECs undergo delocalizing–localizing transition for both attractive and repulsive cases as the strength of the OL or the interatomic interaction is decreased below the critical value. The ring OL can suppress the delocalizing transition efficiently. [Copyright &y& Elsevier]

The antiferromagnetic-semiconductor extreme tensile strain (8%) states of La 0.7 Ca 0.3 MnO 3 membranes was achieved by Hong et al. (2020) [23]. To understand such tunable magnetic and electronic properties in these La 2 3 M 1 3 MnO 3 (M=Ca, Sr) systems, we have investigated the magnetic and electronic behaviors of La 2 3 M 1 3 MnO 3 (M=Ca, Sr) under strain and charge doping using first-principles calculations. A ferromagnetic-semiconductor phase is predicted for La 2 3 Sr 1 3 MnO 3 beyond 4% biaxial tensile strain. Meanwhile, its energy gap and magnetic anisotropic energy increase as the strain increases. We also discover that the change of magnetic exchange energy in La 2 3 Ca 1 3 MnO 3 under charge doping is in analogy to the scenario directly changing the Ca concentrations. Based on the magnetic competition analysis, it is expected that the carrier concentration and strains dominate the magnetic ground state while the La/Ca distributions have little impact. The highly tunable magnetic-electronic properties offer opportunities for the future magnetic-electronic materials design and applications. • DFT SCAN calculations give excellent structure and magnetic moments of the studied systems. • A ferromagnetic semiconductor is predicted for La 2/3 Sr 1/3 MnO 3 under biaxial tensile strain. • Carrier concentration combined with strains dominate the magnetic coupling. • Magnetic anisotropic energy is enhanced by 30 μeV by strains for La 2/3 Sr 1/3 MnO 3. [ABSTRACT FROM AUTHOR]