论文标题
使用移动的dirac $δ$ - 电势井的自旋耦合原子物质波的单向自旋传输
Unidirectional spin transport of a spin-orbit-coupled atomic matter wave using a moving Dirac $δ$-potential well
论文作者
论文摘要
我们使用移动的dirac $δ$势井研究自旋轨道偶联原子物质波的传输。在自旋轨道耦合系统中，可以在地面和激发能级中以dirac $δ$电位形成绑定的状态。由于Galilean不变性在自旋轨耦合系统中破裂，因此电势的移动将诱导速度依赖性的有效失谐。这种引起的失调打破了自旋对称性，并使地面运输频道被旋转-Uparrow $（$ \ downarrow $），而使兴奋状态的运输频道被旋转-$ \ downrow $（$ \ up \ uparrow $），以获得积极的（负区域）运输。当$δ$势井以较小的速度移动时，地面状态和激发状态通道都会有助于运输，因此两个自旋组件都可以有效地运输。但是，当$δ$竞争力的移动速度超过临界值时，诱导的失调足够大以消除激发的绑定状态，并使地面绑定状态为唯一的运输渠道，只有旋转 - $ \ uparrow $（$ \ uparrow $（$ \ \ downarrow $），可以在正（负）方向上有效地运输（负）。这项工作展示了单向自旋传输的原型。
We study the transport of a spin-orbit-coupled atomic matter wave using a moving Dirac $δ$-potential well. In a spin-orbit-coupled system, bound states can be formed in both ground and excited energy levels with a Dirac $δ$ potential. Because Galilean invariance is broken in a spin-orbit-coupled system, moving of the potential will induce a velocity-dependent effective detuning. This induced detuning breaks the spin symmetry and makes the ground-state transporting channel be spin-$\uparrow$ ($\downarrow$) favored while makes the excited-state transporting channel be spin-$\downarrow$ ($\uparrow$) favored for a positive-direction (negative-direction) transporting. When the $δ$-potential well moves at a small velocity, both the ground-state and the excited-state channels contribute to the transportation, and thus both the spin components can be efficiently transported. However, when the moving velocity of the $δ$-potential well exceeds a critical value, the induced detuning is large enough to eliminate the excited bound state, and makes the ground bound state the only transporting channel, in which only the spin-$\uparrow$ ($\downarrow$) component can be efficiently transported in a positive (negative) direction. This work demonstrates a prototype of unidirectional spin transport.
