Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Phys Rev Lett. 2013 May 24;110(21):215301. doi: 10.1103/PhysRevLett.110.215301. Epub 2013 May 21.
We study the properties of dipolar fermions trapped in one-dimensional bichromatic optical lattices and show the existence of fractional topological states in the presence of strong dipole-dipole interactions. We find some interesting connections between fractional topological states in one-dimensional superlattices and the fractional quantum Hall states: (i) the one-dimensional fractional topological states for systems at filling factor ν=1/p have p-fold degeneracy, (ii) the quasihole excitations fulfill the same counting rule as that of fractional quantum Hall states, and (iii) the total Chern number of p-fold degenerate states is a nonzero integer. The existence of crystalline order in our system is also consistent with the thin-torus limit of the fractional quantum Hall state on a torus. The possible experimental realization in cold atomic systems offers a new platform for the study of fractional topological phases in one-dimensional superlattice systems.
我们研究了被囚禁在一维双光子晶格中的偶极费米子的性质，并在强偶极-偶极相互作用下展示了分数拓扑态的存在。我们发现了一维超晶格中的分数拓扑态与分数量子霍尔态之间的一些有趣联系：（i）填充因子 ν=1/p 的系统中的一维分数拓扑态具有 p 重简并，（ii）准粒子激发满足与分数量子霍尔态相同的计数规则，（iii）p 重简并态的总陈数是一个非零整数。我们系统中的晶体有序性也与环上的分数量子霍尔态在薄环极限下的情况一致。在冷原子系统中的可能实验实现为研究一维超晶格系统中的分数拓扑相提供了一个新的平台。
