We report that La60Fe30Al10 metallic glass has clear,reproducible,periodic variation in its differential resistance as a function of a perpendicular magnetic field below its superconducting transition temperature. The...We report that La60Fe30Al10 metallic glass has clear,reproducible,periodic variation in its differential resistance as a function of a perpendicular magnetic field below its superconducting transition temperature. The oscillation period corresponds to a superconducting flux quantum. The observed phenomena originate from the Little-Parks-like resistance oscillations in the cylindrical La nanorod with a high aspect ratio and uniform orientation precipitated on the ribbon surface. The highly-oriented La nanocrystals prepared on a flexible glass substrate offer an opportunity for integrating numerous superconducting circuits into a single chip.展开更多
We propose a scheme to create an effective magnetic field, which can be perceived by cold neutral atoms in a two-dimensional optical lattice, with a laser field with a space-dependent phase and a conventional laser fi...We propose a scheme to create an effective magnetic field, which can be perceived by cold neutral atoms in a two-dimensional optical lattice, with a laser field with a space-dependent phase and a conventional laser field acting on A-type three-level atoms. When the dimensionless parameter a, being the ratio of flux through a lattice cell to one flux quantum, is rational, the energy spectrum shows a fractal band structure, which is so-called Hofstadter＇s butterfly.展开更多
碳纳米卷作为一种新型的碳基纳米材料,其结构非封闭且内径大小容易调控,成为当今材料科学研究热点之一。利用石墨烯碳原子轨道作sp2杂化时π电子的紧束缚模型,考虑波矢k周期性边界条件及轴向磁场的影响,构造了磁场中碳纳米卷的紧束缚模...碳纳米卷作为一种新型的碳基纳米材料,其结构非封闭且内径大小容易调控,成为当今材料科学研究热点之一。利用石墨烯碳原子轨道作sp2杂化时π电子的紧束缚模型,考虑波矢k周期性边界条件及轴向磁场的影响,构造了磁场中碳纳米卷的紧束缚模型,并研究了其在轴向磁场中的能带、能隙及电子态密度等性质。结果表明,碳纳米卷的能量色散是以磁通量子Φ0为周期随磁通量Φ变化,最低未占据分子轨道也随之产生了明显移动,从而导致碳纳米卷发生金属-半导体连续转变,其中ZCNS(15,0)能隙最大为0.878 e V,而ACNS(12,12)为0.654 e展开更多
基金supported by the National Natural Science Foundation of China (51101056, 50731008 and 50921091)the National Basic Research Program of China (2007CB613904)+1 种基金the Fundamental Research Funds for the Central Universities (09Q44)the State Key Lab of Advanced Metals and Materials (2010Z-02)
文摘We report that La60Fe30Al10 metallic glass has clear,reproducible,periodic variation in its differential resistance as a function of a perpendicular magnetic field below its superconducting transition temperature. The oscillation period corresponds to a superconducting flux quantum. The observed phenomena originate from the Little-Parks-like resistance oscillations in the cylindrical La nanorod with a high aspect ratio and uniform orientation precipitated on the ribbon surface. The highly-oriented La nanocrystals prepared on a flexible glass substrate offer an opportunity for integrating numerous superconducting circuits into a single chip.
基金supported by the Teaching and Research Foundation for the Outstanding Young Faculty of Southeast University and National Natural Science Foundation of China under Grant No.10571091
文摘We propose a scheme to create an effective magnetic field, which can be perceived by cold neutral atoms in a two-dimensional optical lattice, with a laser field with a space-dependent phase and a conventional laser field acting on A-type three-level atoms. When the dimensionless parameter a, being the ratio of flux through a lattice cell to one flux quantum, is rational, the energy spectrum shows a fractal band structure, which is so-called Hofstadter＇s butterfly.
文摘碳纳米卷作为一种新型的碳基纳米材料,其结构非封闭且内径大小容易调控,成为当今材料科学研究热点之一。利用石墨烯碳原子轨道作sp2杂化时π电子的紧束缚模型,考虑波矢k周期性边界条件及轴向磁场的影响,构造了磁场中碳纳米卷的紧束缚模型,并研究了其在轴向磁场中的能带、能隙及电子态密度等性质。结果表明,碳纳米卷的能量色散是以磁通量子Φ0为周期随磁通量Φ变化,最低未占据分子轨道也随之产生了明显移动,从而导致碳纳米卷发生金属-半导体连续转变,其中ZCNS(15,0)能隙最大为0.878 e V,而ACNS(12,12)为0.654 e
