Engineering dynamical phase diagrams with driven lattices in spinor gases

We experimentally demonstrate that well-designed driven lattices are versatile tools to simultaneously tune multiple key parameters (namely spin-dependent interactions, spinor phase, and Zeeman energy) for manipulating phase diagrams of spinor gases with negligible heating and atom losses. This opens a new avenue for studying dynamical phase transitions in engineered Hamiltonians. The driven lattice creates additional separatrices in phase space at driving-frequency-determined locations, with progressively narrower separatrices at higher Zeeman energies due to modulation-induced higher harmonics. The vastly expanded range of magnetic fields at which significant spin dynamics occur and improved sensitivities at higher harmonics represent a step towards quantum sensing with ultracold gases.

我们通过实验证明，精心设计的受驱晶格是一种通用工具，可同时调节多个关键参数（即自旋相关相互作用、旋量相位和塞曼能），以便在可忽略加热和原子损失的情况下操控旋量气体的相图。这为研究工程哈密顿量中的动态相变开辟了一条新途径。受驱晶格在相空间中由驱动频率决定的位置产生额外的分界线，由于调制产生的高次谐波，在较高塞曼能下分界线逐渐变窄。发生显著自旋动力学的磁场范围大幅扩展，以及高次谐波处灵敏度的提高，代表着朝着利用超冷气体进行量子传感迈出了一步。