We discuss techniques to engineer effective long-range interactions between polar molecules using external static electric and microwave fields. We consider a setup where molecules are trapped in a two-dimensional pancake geometry by a far-off-resonance optical trap, which ensures the stability of the dipolar collisions. We detail how to modify the shape and the strength of the long-range part of interaction potentials, which can be utilized to realize interesting quantum phases in the context of cold molecular gases.
Inelastic interaction of free-electrons with optical near fields has recently attracted attention for manipulating and shaping free-electron wavepackets. Understanding the nature and the dependence of the inelastic cross section on the polarization of the optical near-field is important for both fundamental aspects and the development of new applications in quantum-sensitive measurements. Here, we investigate the effect of the polarization and the spatial profile of plasmonic near-field distributions on shaping free-electrons and controlling the energy transfer mechanisms, but also tailoring t…
Cooling the trapped atoms toward their motional ground states is key to applications of quantum simulation and quantum computation. By utilizing nonreciprocal couplings between constituent atoms, we present an intriguing dark-state cooling scheme in $Λ$-type three-level structure, which is shown superior than the conventional electromagnetically-induced-transparency cooling in a single atom. The effective nonreciprocal couplings can be facilitated either by an atom-waveguide interface or a free-space photonic quantum link. By tailoring system parameters allowed in dark-state cooling, we identi…
Pendular trapping conditions for ultracold polar molecules enforced by external electric fields
从理论上研究了外磁场和电场同时作用下，超冷极性分子在光晶格中的囚禁条件。我们的结果是基于一个精确的电子结构计算的极性$^{23}$ Na $^{40}$ K极性分子在其绝对基态结合计算其振转超精细运动。我们发现，电场强度的$5.26(15)$千伏/厘米和这个字段和偏振的光学激光之间的角度$54.7^\circ$导致的陷阱设计为$^{23}$钠$^{40}$ K分子的退相干由于激光强度波动和波动的方向上的偏振保持在最低限度。括号中给出了一个标准差系统和统计不确定度。在这种条件下，用于诱导它们之间的可调谐偶极-偶极相互作用的$v=0$分子的超精细旋转态对经历超稳定的匹配捕获力。
The coherent interaction of electromagnetic fields with solid-state two-level systems can yield deterministic quantum light sources for photonic quantum technologies. To date, the performance of semiconductor single-photon sources based on three-level systems is limited mainly due to a lack of high photon indistinguishability. Here, we tailor the cavity-enhanced spontaneous emission from a ladder-type three-level system in a single epitaxial quantum dot (QD) through stimulated emission. After populating the biexciton (XX) of the QD through two-photon resonant excitation (TPE), we use another l…
The control and manipulation of quantum-entangled non-local states is a crucial step for the development of quantum information processing. A promising route to achieve such states on a wide scale is to couple solid-state quantum emitters through their coherent dipole-dipole interactions. Entanglement in itself is challenging, as it requires both nanometric distances between emitters and nearly degenerate electronic transitions. Implementing hyperspectral imaging to identify pairs of coupled organic molecules trapped in a low temperature matrix, we reach distinctive spectral signatures of maxi…
Tailoring Synthetic Gauge Fields in Ultracold Atoms via Spatially Engineered Vector Beams
State Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences（中国科学院光学场调控科学与技术重点实验室）；Research Center on Vector Optical Fields, Institute of Optics and Electronics, Chinese Academy of Sciences（中国科学院光电技术研究所矢量光场研究中心）；College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences（中国科学院大学材料科学与光电技术学院）
We probe electric-field noise in a surface ion trap for ion-surface distances $d$ between 50 and 300 $μ\mathrm{m}$ in the normal and planar directions. We find the noise distance dependence to scale as $d^{-2.6}$ in our trap and a frequency dependence which is consistent with $1/f$ noise. Simulations of the electric-field noise specific to our trap geometry provide evidence that we are not limited by technical noise sources. Our distance scaling data is consistent with a noise correlation length of about 100 $μ\mathrm{m}$ at the trap surface, and we discuss how patch potentials of this size wo…
Microwave state transfer and adiabatic dynamics of magnetically trapped polar molecules
具有非零电子角动量的冷和超冷极性分子在量子化学和控制、新量子体系的研究以及精密测量等方面具有重要的意义。然而，在混合电场和磁场中，这些分子一般受到一个大的避免交叉之间的塞曼子级，在磁陷阱，这些交叉导致扭曲的电位和陷阱的电偏置场的损失。我们的特点是这些交叉的OH微波转移捕获的OH分子从上层|f; M = +3/2>奇偶校验状态到较低|e; +3/2>态，并观察了它们在外加偏置电场下的陷阱动力学。我们的观察是很好地描述了一个简单的朗道-齐纳模型，产生洞察力丰富的光谱和动力学的极性自由基在混合外场。
