Characterizing ultra-narrow momentum of atoms by standing-wave light-pulse sequences

Atomic momentum patterns with narrower interval

We studied the atomic momentum distribution for a superposition of Bloch states spreading in the lowest band of an optical lattice after the action of the standing wave pulse. By designing the imposing pulse on this superposed state, an atomic momentum pattern appears with narrower interval between the adjacent peaks that can be far less than the double recoil momentum. The patterns with narrower interval come from the superposition of the action of the designed pulse on many Bloch states with quasi-momenta over the first Brillouin zone, where for each quasi-momentum there is an interference a…

窄带冷原子光学晶格中吸引型 Fermi-Hubbard 模型的拓扑超流相

Topological superfluid phases of attractive Fermi-Hubbard model in narrow-band cold-atom optical lattices

研究了在 Zeeman 场和 Rashba SOC 下窄带二维吸引型 Fermi-Hubbard 模型的拓扑超流相，通过自洽平均场近似揭示了复杂相图，并发现拓扑能隙在特定参数下可达相互作用强度的 10-12.5%。

Probing and characterizing the growth of a crystal of ultracold bosons and light

The non-linear coupled particle light dynamics of an ultracold gas in the field of two independent counter-propagating laser beams can lead to the dynamical formation of a self-ordered lattice structure as presented in Phys. Rev. X 6, 021026 (2016). Here we present new numerical studies on experimentally observable signatures to monitor the growth and properties of such a crystal in real time. While, at least theoretically, optimal non-destructive observation of the growth dynamics and the hallmarks of the crystalline phase can be performed by analyzing the scattered light, monitoring the evol…

锶$^{3}\mathrm{P}_{2}$亚稳态中的窄线宽介导的Sisyphus冷却

Narrow-line-mediated Sisyphus cooling in the $^{3}\mathrm{P}_{2}$ metastable state of strontium

本文演示了锶$^{3}\mathrm{P}_{2}$态中窄线宽介导的Sisyphus冷却，结合多普勒冷却实现高效冷却，并通过光泵浦实现连续输出，原子数提升两倍，适用于下一代量子传感器。

Observation of momentum-space chiral edge currents in room-temperature atoms

Chiral edge currents play an important role in characterizing topological matter. In atoms, they have been observed at such a low temperature that the atomic motion can be measured. Here we report the first experimental observation of chiral edge currents in atoms at room temperature. Staggered magnetic fluxes are induced by the spatial phase difference between two standing-wave light fields, which couple atoms to form a momentum-space zigzag superradiance lattice. The chiral edge currents have been measured by comparing the directional superradiant emissions of two timed Dicke states in the l…

利用非相干光对量子气体近表面进行吸收成像

Absorption imaging of quantum gases near surfaces using incoherent light

本研究提出了一种利用非相干光对近表面量子气体进行高精度吸收成像的方法，有效抑制了传统成像中的相干伪影和干涉条纹，提升了微米尺度复杂表面成像的可靠性。