Tsui T-C, Wang Y, Subhankar S, Porto J V, Rolston S L
Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, College Park, Maryland 20742, USA.
Phys Rev A (Coll Park). 2020;101(4). doi: 10.1103/physreva.101.041603.
Optical lattices are typically created via the ac Stark shift and are limited by diffraction to periodicities ⩾ /2, where is the wavelength of light used to create them. Lattices with smaller periodicities may be useful for many-body physics with cold atoms and can be generated by stroboscopic application of a phase-shifted lattice with subwavelength features. Here we demonstrate a /4-spaced lattice by stroboscopically applying optical Kronig-Penney-like potentials which are generated using spatially dependent dark states. We directly probe the periodicity of the /4-spaced lattice by measuring the average probability density of the atoms loaded into the ground band of the lattice. We measure lifetimes of atoms in this lattice and discuss the mechanisms that limit the applicability of this stroboscopic approach.
光学晶格通常通过交流斯塔克位移产生，并且受限于衍射，其周期≥λ/2，其中λ是用于创建它们的光的波长。具有更小周期的晶格对于冷原子的多体物理可能是有用的，并且可以通过频闪应用具有亚波长特征的相移晶格来生成。在这里，我们通过频闪应用类似光学克罗尼格-彭尼势来演示一个λ/4间距的晶格，该势是利用空间相关的暗态产生的。我们通过测量加载到晶格基态带中的原子的平均概率密度，直接探测λ/4间距晶格的周期。我们测量了该晶格中原子的寿命，并讨论了限制这种频闪方法适用性的机制。
