我们建议一个计划创造一个有效磁场,它能被冷中立原子在一个二维的光格子察觉,与有一个空间依赖者阶段的一块激光地和在 Λ-type 上扮演三水平的原子的一块常规激光地。什么时候尺寸更少参数 α ,是通过到一流动量的一个格子房间的流动的比率,是合理的,能量光谱显示出分数维的乐队结构,它是所谓的霍夫施塔特的蝴蝶。
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.