Ruseckas J, Juzeliūnas G, Ohberg P, Fleischhauer M
Institute of Theoretical Physics and Astronomy of Vilnius University, A. Gostauto 12, 01108 Vilnius, Lithuania.
Phys Rev Lett. 2005 Jul 1;95(1):010404. doi: 10.1103/PhysRevLett.95.010404. Epub 2005 Jun 28.
We show that the adiabatic motion of ultracold, multilevel atoms in spatially varying laser fields can give rise to effective non-Abelian gauge fields if degenerate adiabatic eigenstates of the atom-laser interaction exist. A pair of such degenerate dark states emerges, e.g., if laser fields couple three internal states of an atom to a fourth common one under pairwise two-photon-resonance conditions. For this so-called tripod scheme we derive general conditions for truly non-Abelian gauge potentials and discuss special examples. In particular we show that using orthogonal laser beams with orbital angular momentum an effective magnetic field can be generated that has a monopole component.
我们证明，如果原子 - 激光相互作用存在简并绝热本征态，那么在空间变化的激光场中，超冷多能级原子的绝热运动会产生有效的非阿贝尔规范场。例如，如果激光场在双光子共振条件下将原子的三个内态耦合到第四个共同态，就会出现一对这样的简并暗态。对于这种所谓的三脚架方案，我们推导了真正非阿贝尔规范势的一般条件并讨论了特殊例子。特别地，我们表明使用具有轨道角动量的正交激光束可以产生一个具有单极分量的有效磁场。
