The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered A...The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered Au1-xCux alloys. From characteristic atom occupation （CAO） patterns of L12-Au3Cu, L12-AuCu3 and Llo-AuCu compounds, their electronic structures, volumetric and energetic properties were calculated. The CAO pattern of Johasson-Linde（J-L） model shows that the transition AuCuI→AuCulI is an exothermic and volume contraction reaction, which is opposite from experimental phenomena. According to CAO pattern of Guymont-Feutelais-Legendre（G-F-L） model, the AuCulI cell consists of two periodic antidirection （PAD） AuCuI regions and two PAD boundary regions. The equations derived from CAO pattern of G-F-L model can be used to calculate energetic properties, volumetric properties and ordering degrees of the PAD AuCuI region and PAD boundary region, as well as corresponding average properties of the AuCulI phase. The results are consistent with experimental phenomena.展开更多
Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can ...Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can overcome this disadvantage and enable lots of promising applications. Here, two novel types of optically induced square lattices, i.e., the amplitude and phase lattices, are proposed in an ultracold atoms ensemble by interfering four ordinary plane waves under different parameter conditions. We demonstrate that in the far-field regime, the atomic amplitude lattice with high transmissivity behaves similarly to an ideal pure sinusoidal amplitude lattice, whereas the atomic phase lattices capable of producing phase excursion across a weak probe beam along with high transmissivity remains equally ideal. Moreover, we identify that the quality of Talbot imaging about a phase lattice is greatly improved when compared with an amplitude lattice. Such an atomic lattice could find applications in alloptical switching at the few photons level and paves the way for imaging ultracold atoms or molecules both in the near-field and in the far-field with a nondestructive and lensless approach.展开更多
基金Project (50711181) supported by the National Natural Science Foundation of China Project (2009FJ4016) supported by Natural Science Foundation of Hunan Province,China
文摘The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered Au1-xCux alloys. From characteristic atom occupation （CAO） patterns of L12-Au3Cu, L12-AuCu3 and Llo-AuCu compounds, their electronic structures, volumetric and energetic properties were calculated. The CAO pattern of Johasson-Linde（J-L） model shows that the transition AuCuI→AuCulI is an exothermic and volume contraction reaction, which is opposite from experimental phenomena. According to CAO pattern of Guymont-Feutelais-Legendre（G-F-L） model, the AuCulI cell consists of two periodic antidirection （PAD） AuCuI regions and two PAD boundary regions. The equations derived from CAO pattern of G-F-L model can be used to calculate energetic properties, volumetric properties and ordering degrees of the PAD AuCuI region and PAD boundary region, as well as corresponding average properties of the AuCulI phase. The results are consistent with experimental phenomena.
基金National Natural Science Foundation of China(NSFC)(61605155,61627812)Fundamental Research Funds for the Central Universities
文摘Conventional periodic structures usually have nontunable refractive indices and thus lead to immutable photonic bandgaps. A periodic structure created in an ultracold atoms ensemble by externally controlled light can overcome this disadvantage and enable lots of promising applications. Here, two novel types of optically induced square lattices, i.e., the amplitude and phase lattices, are proposed in an ultracold atoms ensemble by interfering four ordinary plane waves under different parameter conditions. We demonstrate that in the far-field regime, the atomic amplitude lattice with high transmissivity behaves similarly to an ideal pure sinusoidal amplitude lattice, whereas the atomic phase lattices capable of producing phase excursion across a weak probe beam along with high transmissivity remains equally ideal. Moreover, we identify that the quality of Talbot imaging about a phase lattice is greatly improved when compared with an amplitude lattice. Such an atomic lattice could find applications in alloptical switching at the few photons level and paves the way for imaging ultracold atoms or molecules both in the near-field and in the far-field with a nondestructive and lensless approach.
