The Stark effect provides a powerful method to shift the spectra of molecules, atoms, and electronic transitions in general, becoming one of the simplest and most straightforward ways to tune the frequency of quantum emitters by means of a static electric field. At the same time, in order to reduce the emitter sensitivity to charge noise, inversion symmetric systems are typically designed, providing a stable emission frequency with a quadratic-only dependence on the applied field. However, such nonlinear behavior might be reflected in correlations between the tuning ability and unwanted spectral fluctuations. Here, we provide experimental evidence of this trend using molecular quantum emitters in the solid state cooled down to liquid helium temperatures. We finally combine the electric field generated by electrodes, which is parallel to the molecule’s induced dipole, with optically excite long-lived charge states acting in the perpendicular direction. Based on the anisotropy of the molecule’s polarizability, our two-dimensional control of the local electric field allows us not only to tune the emitter’s frequency but also to sensibly suppress the spectral instabilities associated with field fluctuations.

中文翻译：

---

增强对单分子发射频率和光谱扩散的控制


斯塔克效应提供了一种强大的方法来移动分子、原子和电子跃迁的光谱，成为通过静电场调整量子发射器频率的最简单、最直接的方法之一。同时，为了降低发射器对电荷噪声的敏感性，通常设计反转对称系统，提供稳定的发射频率，并且仅对外加场产生二次方依赖性。但是，这种非线性行为可能反映在调谐能力和不需要的频谱波动之间的相关性中。在这里，我们使用冷却到液氦温度的固态分子量子发射器提供了这一趋势的实验证据。最后，我们将电极产生的电场（平行于分子的感应偶极子）与沿垂直方向作用的长寿命电荷态的光激发相结合。基于分子极化率的各向异性，我们对局部电场的二维控制不仅使我们能够调整发射器的频率，还可以合理地抑制与场波动相关的频谱不稳定性。