Observation of Lasing Mediated by Collective Atomic Recoil

Robust generation of entanglement in Bose-Einstein condensates by collective atomic recoil

We address the dynamics induced by collective atomic recoil in a Bose-Einstein condensate in presence of radiation losses and atomic decoherence. In particular, we focus on the linear regime of the lasing mechanism, and analyze the effects of losses and decoherence on the generation of entanglement. The dynamics is that of three bosons, two atomic modes interacting with a single-mode radiation field, coupled with a bath of oscillators. The resulting three-mode dissipative Master equation is solved analytically in terms of the Wigner function. We examine in details the two complementary limits …

反冲诱导误差及其在原子量子比特间光子介导纠缠中的校正

Recoil-induced errors and their correction in photon-mediated entanglement between atom qubits

本文研究原子运动对光子介导纠缠的影响，提出反冲算符描述并给出预示后分离量子比特与运动的校正方法，以提升远距离量子网络中的纠缠保真度与速率。

连续动量态激射与使用激光冷却锶原子的腔频率钉扎

Continuous momentum state lasing and cavity frequency-pinning with laser-cooled strontium atoms

本文利用连续加载到环形腔中的激光冷却$^{88}$Sr原子，实现了长达数小时的连续动量态激射，并通过原子损失机制将激射频率对腔频率变化的敏感度抑制了120倍，为连续腔QED量子模拟和超辐射激光器开辟了新路径。

Tailoring Near-Field-Mediated Photon Electron Interactions with Light Polarization

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…

Strong optical coupling through superfluid Brillouin lasing

Brillouin scattering has applications ranging from signal processing, sensing and microscopy, to quantum information and fundamental science. Most of these applications rely on the electrostrictive interaction between light and phonons. Here we show that in liquids optically-induced surface deformations can provide an alternative and far stronger interaction. This allows the demonstration of ultralow threshold Brillouin lasing and strong phonon-mediated optical coupling for the first time. This form of strong coupling is a key capability for Brillouin-reconfigurable optical switches and circui…

Cavity-enhanced superradiant Rayleigh scattering with ultra-cold and Bose-Einstein condensed atoms

We report on the observation of collective atomic recoil lasing and superradiant Rayleigh scattering with ultracold and Bose-Einstein condensed atoms in an optical ring cavity. Both phenomena are based on instabilities evoked by the collective interaction of light with cold atomic gases. This publication clarifies the link between the two effects. The observation of superradiant behavior with thermal clouds as hot as several tens of $μ\textrm{K}$ proves that the phenomena are driven by the cooperative dynamics of the atoms, which is strongly enhanced by the presence of the ring cavity.

里德堡原子中通过光子反冲实现宏观位置-位置纠缠

Macroscopic position-position entanglement by photon recoil in Rydberg atoms

研究通过里德堡阻塞和光子反冲，在两个空间分离的中性原子间实现位置-位置纠缠态，形成贝尔态，纠缠存于原子位置，两位置间距可达百微米量级。

有限阱深对量子发射体阵列暗态衰减、反冲和退相干的影响

Effects of finite trapping on the decay, recoil, and decoherence of dark states of quantum emitter arrays

本文研究了有限阱深和光介导力对量子发射体阵列中亚辐射态的影响，发现这些效应会导致衰减率随时间变化、振动能量转移及状态混合，并提出了通过优化阵列配置以减轻退相干的策略。

时间箱光子介导的囚禁原子的高保真远程纠缠

High-fidelity remote entanglement of trapped atoms mediated by time-bin photons

本研究通过时间箱光子介导实现了远程囚禁原子量子比特存储器间的高保真纠缠，利用基于测量的错误检测和抑制原子反冲误差，达到97%的纠缠保真度，并证明超过99.9%的保真度是可行的。

Atomic selfordering in a ring cavity with counterpropagating pump

The collective dynamics of mobile scatterers and light in optical resonators generates complex behaviour. For strong transverse illumination a phase transition from homogeneous to crystalline particle order appears. In contrast, a gas inside a single-side pumped ring cavity exhibits an instability towards bunching and collective acceleration called collective atomic recoil lasing (CARL). We demonstrate that by driving two orthogonally polarized counter propagating modes of a ring resonator one realises both cases within one system. The corresponding phase diagram depending on the two pump inte…

Incoherent quantum feedback control of collective light scattering by Bose-Einstein condensates

It is well known that in the presence of a ring cavity the light scattering from a uniform atomic ensemble can become unstable resulting in the collective atomic recoil lasing. This is the result of a positive feedback due to the cavity. We propose to add an additional electronic feedback loop based on the photodetection of the scattered light. The advantage is a great flexibility in choosing the feedback algorithm, since manipulations with electric signals are very well developed. In this paper we address the application of such a feedback to atoms in the Bose-Einstein condensed state and exp…

连续腔量子电动力学与原子束

Continuous cavity-QED with an atomic beam

该研究设计了一种产生连续原子束穿过光学腔的装置，实现集体强耦合并测量连续光学增益，为连续超辐射激光等集体现象的阈值条件研究奠定基础。

自组织原子晶体中戈德斯通模的随机输运

Stochastic transport of a Goldstone mode in a self-organized atomic crystal

本文在光学环形腔中追踪自组织原子晶体的戈德斯通模随机输运，发现扩散常数随$1/N$减小，归一化后呈普适曲线，拓展了连续对称性破缺的研究范畴。