Demonstration of a Cold Atom Fountain Electron Electric Dipole Moment Experiment

Demonstration of sensitivity increase in mercury free-spin-precession magnetometers due to laser-based readout for neutron electric dipole moment searches

We report on a laser based $^{199}$Hg co-magnetometer deployed in an experiment searching for a permanent electric dipole moment of the neutron. We demonstrate a more than five times increased signal to-noise-ratio in a direct comparison measurement with its $^{204}$Hg discharge bulb-based predecessor. An improved data model for the extraction of important system parameters such as the degrees of absorption and polarization is derived. Laser- and lamp-based data-sets can be consistently described by the improved model which permits to compare measurements using the two different light sources …

偶极-偶极相互作用修饰的稳态暗态极化子的实验演示

Experimental Demonstration of Stationary Dark-State Polaritons Dressed by Dipole-Dipole Interaction

实验演示了偶极-偶极相互作用修饰的稳态暗态极化子，其相移与理论一致，为实现高温三维玻色-爱因斯坦凝聚奠定基础。

Proposed search for an electric-dipole moment using laser-cooled $^{171}$Yb atoms

We propose an experiment to search for a permanent atomic electric-dipole moment (EDM) using laser-cooled $^{171}$Yb atoms launched in an atomic fountain. A uniform B field sets the quantization axis, and the Ramsey separated-oscillatory-fields method is used to measure the Zeeman precession frequency of the atoms. Laser beams of appropriate polarization are used for preparation and detection in a given magnetic sublevel. The signature of an EDM is a shift in the Ramsey resonance correlated with application of a large E field. The precision is expected to be at least 20 times better than curre…

Suppression of single cesium atom heating in a microscopic optical dipole trap for demonstration of an 852nm triggered single-photon source

We investigate single cesium (Cs) atom heating owing to the momentum accumulation process induced by the resonant pulsed excitation in a microscopic optical dipole trap formed by a strongly focused 1064 nm laser beam. The heating depends on the trap frequency which restricts the maximum repetition rate of pulsed excitation. We experimentally verify the heating of a single atom and then demonstrate how to suppress it with an optimized pulsed excitation/cooling method. The typical trap lifetime of single Cs atom is extended from 108 +/- 6 us to 2536 +/- 31 ms, and the corresponding number of exc…

Magnetic dipolar interaction between hyperfine clock states in a planar alkali Bose gas

In atomic systems, clock states feature a zero projection of the total angular momentum and thus a low sensitivity to magnetic fields. This makes them widely used for metrological applications like atomic fountains or gravimeters. Here, we show that a mixture of two such non-magnetic states still display magnetic dipole-dipole interactions. Using high resolution spectroscopy of a planar gas of $^{87}$Rb atoms with a controlled in-plane shape, we explore the effective isotropic and extensive character of these interactions and demonstrate their tunability. Our measurements set strong constraint…

用于TUCAN电偶极矩实验的无磁光泵磁强计的演示

Demonstration of magnetically silent optically pumped magnetometers for the TUCAN electric dipole moment experiment

本研究演示了一款用于TUCAN电偶极矩实验的无磁光泵铯磁强计，其具备高灵敏度与高稳定性，支持单激光驱动多传感器，可用于高灵敏度磁学测量场景。

Experimental demonstration of a Rydberg-atom beam splitter

Inhomogeneous electric fields generated above two-dimensional electrode structures have been used to transversely split beams of helium Rydberg atoms into pairs of spatially separated components. The atomic beams had initial longitudinal speeds of between 1700 and 2000 m/s and were prepared in Rydberg states with principle quantum number $n=52$ and electric dipole moments of up to 8700 D by resonance-enhanced two-color two-photon laser excitation from the metastable 1s2s $^3$S$_1$ level. Upon exiting the beam splitter the ensembles of Rydberg atoms were separated by up to 15.6 mm and were dete…

氦-3的魔装演示

Demonstration of magic dressing of $^3$He

该研究通过魔装饰方法实现了氦-3和中子旋磁比的临界装饰，提高了磁场梯度下的横向弛豫时间。

量子退火在磁偶极超精细结构常数中的应用：原子能量以外的首批结果

Applications of quantum annealing to magnetic dipole hyperfine structure constants: First results beyond energies for atoms

采用改进的量子退火特征求解器算法，在D-Wave量子硬件上计算了Li、Be、Na、Mg的磁偶极超精细结构常数，结果与GRASP程序一致，精度达小数点后三位。

Rydberg Aggregates

We review Rydberg aggregates, assemblies of a few Rydberg atoms exhibiting energy transport through collective eigenstates, considering isolated atoms or assemblies embedded within clouds of cold ground-state atoms. We classify Rydberg aggregates, and provide an overview of their possible applications as quantum simulators for phenomena from chemical or biological physics. Our main focus is on flexible Rydberg aggregates, in which atomic motion is an essential feature. In these, simultaneous control over Rydberg-Rydberg interactions, external trapping and electronic energies, allows Born-Oppen…

Coherent microwave-to-optical conversion via six-wave mixing in Rydberg atoms

We present an experimental demonstration of converting a microwave field to an optical field via frequency mixing in a cloud of cold $^{87}$Rb atoms, where the microwave field strongly couples to an electric dipole transition between Rydberg states. We show that the conversion allows the phase information of the microwave field to be coherently transferred to the optical field. With the current energy level scheme and experimental geometry, we achieve a photon conversion efficiency of ~0.3% at low microwave intensities and a broad conversion bandwidth of more than 4 MHz. Theoretical simulation…

Coupling single atoms to a nanophotonic whispering-gallery-mode resonator via optical guiding

We demonstrate an efficient optical guiding technique for coupling cold atoms in the near field of a planar nanophotonic circuit, and realize large atom-photon coupling to a whispering-gallery mode in a microring resonator with a single-atom cooperativity $C\gtrsim 8$. The guiding potential is created by diffracted light on a nanophotonic waveguide that smoothly connects to a dipole trap in the far field for atom guiding with subwavelength precision. We observe atom-induced transparency for light coupled to a microring, characterize the atom-photon coupling rate, extract guided atom flux, and …