"In the scope of this project we aimed at investigating topological superfluid states of matter with gases of Dysprosium atoms prepared at temperature close to absolute zero (-273.15°C). At this ultra-low temperatures, matter starts to reveal its quantum nature. In particular, below a certain ""critical"" temperature, the gas might undergo a phase transition into the superfluid state. Realization of the superfluid with topologicaly non-trivial properties, according to the recent proposals, requires introducing a strong and tunable SOC in the system, typically by means of laser light interacting with atoms. It turns out, however, that even with a very careful choice of coupling parameters, the unavoidable heating due to the scattering of the photons by atoms is strong enough to destroy the superfluid state way before any interesting measurements are done. Luckily, in particular case of Dysprosium atoms (Lanthanide group), the heating is about hundred times weaker, so we may create and study topological superfluid on realistic timescales.
In the initial phase of the project we have realized that a comprehensive study of SOC phenomena would first require a significant improvement on stability of our experimental apparatus. In the field of ultracold atoms we experimentally produce atomic gases at ultra-low temperatures using laser light to decelerate, trap and cool the atoms. One of the workhorses in laser cooling is the so-called magneto-optical trap (MOT), where the pre-slowed atoms are captured and further cooled with the aid of specific combination of optical and magnetic forces. The MOT of Dysprosium atoms has several non-trivial properties, which were not studied extensively as it is relatively new specie in our field. With a series of detailed experiments and development of theoretical models, we obtained at the first time a quantitative description of MOTs of the Lanthanides, which will serve as a benchmark for future experiments with this class of atoms. The results were published in the peer-reviewed journal.
In scope of this project we have implemented the setups for radio-frequency and so-called Feshbach spectroscopy (a technique widely used for probing properties of inter-atomic interactions at ultra-low temperatures) that served in numerous calibrations and fine-tunings of our system and proved to be indispensable tools. We also started testing a new high-resolution imaging system and plan to implement it in few months, completing thereby the list of minimum necessary ""hardware"" developments planned within the project. During the last phase of the project, we have started experiments on atom-light interaction with Dysprosium atoms with a prospect of implementing SOC in our setup and testing the feasibility of creating topological superfluid state. The atom-light interaction for Lanthanide atoms is very rich and almost unexplored topic and we expect the results of ongoing experiments to be published in peer-reviewed journal before the end of the year 2017.
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