Interacting quantum mixtures for precision atom interferometry

Practical limits for large-momentum-transfer clock atom interferometers

Atom interferometry on optical clock transitions is being pursued for numerous long-baseline experiments both terrestrially and for future space missions. Crucial to meeting these experiments' required sensitivities is the implementation of large momentum transfer ($>$10$^3\hbar k$). Here we show that to sequentially apply such a large momentum via $π$ pulses places stringent requirements on the frequency noise of the interferometry laser, finding that the linewidth is required to be considerably lower than has previously been suggested. This is due to imperfect pulse fidelity in the presence …

Resonantly Interacting Fermi-Fermi Mixture of $^{161}$Dy and $^{40}$K

We report on the realization of a Fermi-Fermi mixture of ultracold atoms that combines mass imbalance, tunability, and collisional stability. In an optically trapped sample of $^{161}$Dy and $^{40}$K, we identify a broad Feshbach resonance centered at a magnetic field of $217\,$G. Hydrodynamic expansion profiles in the resonant interaction regime reveal a bimodal behavior resulting from mass imbalance. Lifetime studies on resonance show a suppression of inelastic few-body processes by orders of magnitude, which we interpret as a consequence of the fermionic nature of our system. The resonant m…

Universal and anomalous behavior in the thermalization of strongly interacting harmonically trapped gas mixtures

We report on the dynamics of thermalization by extending a generalization of the Caldeira-Leggett model, developed in the context of cold atomic gases confined in a harmonic trap, to higher dimensions. Universal characteristics en route to thermalization which appear to be independent of dimensionality are highlighted, which additionally suggest a scaling analogous to turbulent mixing in fluid dynamics. We then focus on features dependent on dimensionality, with particular regard to the role of angular momentum of the two atomic clouds, having in mind the goal of efficient thermalization betwe…

Dynamics of Feshbach Molecules in an Ultracold Three-Component Mixture

We present investigations of the formation rate and collisional stability of lithium Feshbach molecules in an ultracold three-component mixture composed of two resonantly interacting fermionic 6-Li spin states and bosonic 174-Yb. We observe long molecule lifetimes (> 100 ms) even in the presence of a large ytterbium bath and extract reaction rate coefficients of the system. We find good collisional stability of the mixture in the unitary regime, opening new possibilities for studies and probes of strongly interacting quantum gases in contact with a bath species.

Progress towards quantum-enhanced interferometry with harmonically trapped quantum matter-wave bright solitons

We model the dynamics of attractively interacting ultracold bosonic atoms in a quasi-one-dimensional wave-guide with additional harmonic trapping. Initially, we prepare the system in its ground state and then shift the zero of the harmonic trap and switch on an additional narrow scattering potential near the center of the trap. After colliding with the barrier twice, we propose to measure the number of atoms opposite to the initial condition. Quantum-enhanced interferometry with quantum bright solitons allows us to predict detection of an offset of the scattering potential with considerably in…

玻色玻璃相的量子气体显微镜与塔尔博干涉仪研究

Quantum-gas microscopy and Talbot interferometry of the Bose-glass phase

研究通过量子气体显微镜与塔尔博干涉仪测量玻色玻璃相的相干长度，利用单原子分辨探测和超冷原子在二维晶格中的有序势，揭示玻色玻璃相的特征，并观察非平衡动力学的迹象。

从超流不稳定性和激发特性角度看强相互作用2D-3D费米-费米混合体系的维度性

Dimensionality of a strongly interacting 2D-3D Fermi-Fermi mixture from the perspective of superfluid instability and excitation properties

利用自洽T矩阵近似研究不同维度带间配对形成的吸引相互作用费米原子气体，发现混合维度增强的配对涨落使超流转变温度在2D-3D极限下被压制至零，而赝能隙现象则呈现3D特征，表明强相互作用费米气体的维度性取决于观测对象。