Center for Subwavelength Optics and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
Phys Rev Lett. 2013 Dec 13;111(24):245301. doi: 10.1103/PhysRevLett.111.245301. Epub 2013 Dec 10.
For a spin-carrying particle moving in a spatially varying magnetic field, effective electromagnetic forces can arise due to the geometric phase associated with adiabatic spin rotation of the particle. We report the observation of a geometric Hall effect in a spinor Bose-Einstein condensate with a Skyrmion spin texture. Under translational oscillations of the spin texture, the condensate resonantly develops a circular motion in a harmonic trap, demonstrating the existence of an effective Lorentz force. When the condensate circulates, quantized vortices are nucleated in the boundary region of the condensate and the vortex number increases over 100 without significant heating. We attribute the vortex nucleation to the shearing effect of the effective Lorentz force from the inhomogeneous effective magnetic field.
对于在空间变化的磁场中运动的携带自旋的粒子，由于与粒子绝热自旋旋转相关的几何相位，可能会产生有效的电磁力。我们在具有Skyrmion 自旋结构的自旋玻色-爱因斯坦凝聚体中观察到了几何 Hall 效应。在自旋结构的平移振荡下，凝聚体在谐波陷阱中共振地发展出圆形运动，证明了有效洛伦兹力的存在。当凝聚体循环时，在凝聚体的边界区域中会产生量子涡旋，并且在没有明显加热的情况下，涡旋数增加了 100 以上。我们将涡旋的产生归因于不均匀有效磁场的有效洛伦兹力的剪切效应。
