论文标题
拓扑电荷抽水与次波长拉曼晶格
Topological charge pumping with subwavelength Raman lattices
论文作者
论文摘要
最近的实验表明，使用$ n $内部状态与波长$λ$的激光器偶联的原子具有深度的次波长晶格。所得的单元单元为$λ/2n $的程度，与通常的$λ/2 $ $λ/2 $ $ fold折叠。对于共振拉曼耦合，该晶格由$ n $独立的正弦电位（带有$λ/2 $的周期$λ/2 $）组成，彼此之间被$λ/2N $置换。我们表明，从拉曼共振中引起的引起这些电势之间的隧道。定期调节引人入胜的夫妻$ s $ - 和$ p $ - 带潜能的频带，从而形成了一对耦合的亚波长米 - 米勒连锁店。这是一个新型的拓扑泵，违反直觉可以分别给出每个水稻链的每个泵周期的位移的一半。我们通过无限系统Chern数字分析描述了这种行为，并在数值上识别了相关的有限系统边缘状态。
Recent experiments demonstrated deeply subwavelength lattices using atoms with $N$ internal states Raman-coupled with lasers of wavelength $λ$. The resulting unit cell was $λ/2N$ in extent, an $N$-fold reduction compared to the usual $λ/2$ periodicity of an optical lattice. For resonant Raman coupling, this lattice consists of $N$ independent sinusoidal potentials (with period $λ/2$) displaced by $λ/2N$ from each other. We show that detuning from Raman resonance induces tunneling between these potentials. Periodically modulating the detuning couples the $s$- and $p$-bands of the potentials, creating a pair of coupled subwavelength Rice--Mele chains. This operates as a novel topological charge pump that counter-intuitively can give half the displacement per pump cycle of each individual Rice--Mele chain separately. We analytically describe this behavior in terms of infinite-system Chern numbers, and numerically identify the associated finite-system edge states.
