论文标题
纳米纤维引导的光场与两级原子之间的方向依赖性耦合，并具有电动四极转变
Direction-dependent coupling between a nanofiber-guided light field and a two-level atom with an electric quadrupole transition
论文作者
论文摘要
我们研究了纳米纤维引导的光场和具有电动四极转变的两级原子之间耦合的定向依赖性。 We examine the situation where the atom lies on the fiber transverse axis $x$, the quantization axis for the atomic internal states is the other orthogonal transverse axis $y$, the atomic upper and lower levels are the magnetic sublevels $M'$ and $M$ of hyperfine-structure levels of an alkali-metal atom, and the field is in a quasilinearly polarized fundamental guided mode He $ _ {11} $带有偏光$ξ= x $或$ y $。我们发现，在（$ m'-m = \ pm1 $，$之一，$ = y $）和（$ m'-m = \ pm2 $，$ pm2 $，$之一，$ξ= x $）的情况下，四极杆频率的绝对值取决于光场的传播方向。我们表明，耦合的方向依赖性导致自发发射对引导模式的方向依赖性。我们发现，在四极转变的情况下，原子场耦合的定向依赖性并不完全是由于光的自旋轨道耦合：由于该场空间相位因子的梯度，还有其他一些贡献。
We study the directional dependence of the coupling between a nanofiber-guided light field and a two-level atom with an electric quadrupole transition. We examine the situation where the atom lies on the fiber transverse axis $x$, the quantization axis for the atomic internal states is the other orthogonal transverse axis $y$, the atomic upper and lower levels are the magnetic sublevels $M'$ and $M$ of hyperfine-structure levels of an alkali-metal atom, and the field is in a quasilinearly polarized fundamental guided mode HE$_{11}$ with the polarization $ξ=x$ or $y$. We find that the absolute value of the quadrupole Rabi frequency depends on the propagation direction of the light field in the cases of ($M'-M=\pm1$, $ξ=y$) and ($M'-M=\pm2$, $ξ=x$). We show that the directional dependence of the coupling leads to the directional dependence of spontaneous emission into guided modes. We find that the directional dependence of the atom-field coupling in the case of quadrupole transitions is not entirely due to spin-orbit coupling of light: there are some other contributions resulting from the gradient of the spatial phase factor of the field.
