AI 中文总结
本研究在超冷玻色气体中实现了畴壁输运的相干控制，通过调控自旋畴取向改变畴壁轨迹，揭示了两种输运 regime 的交叉，为原子电子学系统的可控畴壁动力学提供了新途径。
AI 中文摘要
畴壁是自旋输运的载体，其可控操控是多种自旋电子学和信息处理技术的基础。本研究在弱相互作用的非简并超冷玻色气体中实现了可调控的畴壁输运：我们初始化了三畴赝自旋-1/2结构，观察到由交换介导的自旋电流驱动的长寿命畴壁的自发传播；通过改变自旋畴的取向，我们调控了畴壁两侧自旋电流的平衡，进而调整畴壁的轨迹，包括初始运动方向的反转。测量结果揭示了两种 regime 的交叉：一种是交换稳定 regime，其中相干自旋交换碰撞抑制畴壁运动；另一种是扩散主导 regime，其特征为热速度下的快速输运。量子玻尔兹曼方程的数值解重现了观测到的动力学，并确定横向相位梯度是调控畴壁传播的重要控制参数。这些结果将相干性和相位工程确立为超冷气体中自旋输运的调控工具，并为原子电子学系统中可控的畴壁动力学提供了途径。
英文摘要
Domain walls are carriers of spin transport whose controlled manipulation underlies a wide range of spintronic and information-processing technologies. Here we demonstrate tunable domain-wall transport in a weakly interacting nondegenerate ultracold Bose gas. We initialize a three-domain pseudo-spin-1/2 texture and observe spontaneous propagation of long-lived domain walls driven by exchange-mediated spin currents. By varying the orientation of the spin domains, we control the balance of spin currents across the walls and thereby tune their trajectories, including reversals of the initial direction of motion. Measurements reveal a crossover from an exchange-stabilized regime, in which coherent spin-exchange collisions suppress wall motion, to a diffusion-dominated regime characterized by rapid transport at thermal velocities. Numerical solutions of a quantum Boltzmann equation reproduce the observed dynamics and identify transverse phase gradients as an important control parameter governing domain-wall propagation. These results establish coherence and phase engineering as tools for programming spin transport in ultracold gases and provide a route toward controllable domain-wall dynamics in atomtronic systems.
