Nona Semana Integrada do Instituto de Física de São Carlos

Investigation of superfluid properties in a quantum degenerate mixture of sodium and potassium: implementation of feshbach resonances

Não agendado

20m

Mestrado

Palestrante

Pedro Mazo (Universidade de São Paulo - Instituto de Física de São Carlos )

Descrição

The objective of our global project is to produce a Bose-Einstein Condensate (BEC) of two bosonic species (Sodium23 and Potassium41-39) with the possibility to vary the interspecies interaction for the study of the superfluid aspects in different regimes.(1)Both species are loaded separately in 2D Magneto-Optical Traps (2D MOT) and then pushed to the main chamber and captured in a 3D MOT where further cooling processes can take place and we can finally transfer the cloud to a pure optical trap where we obtain a quantum degenerate mixture.(1)Through the use of techniques as Stirring Beam and Feshbach Resonances (2) will be possible the study of the nucleation of vortices in a two species BEC with tunable interactions, exploring the different miscibility regimes between Na and K, as well as formation and studies in Quantum Turbulence. In this work we focus on the implementation and tuning of the Feshbach Resonances between species: utilizing an homogeneous magnetic field we can change the sign and the magnitude of the interactions in our system. For the magnetic field we will use the quadrupole coils from the magnetic trap, switching it from Anti-Helmholtz to Helmholtz configuration through an H-bridge. (3)This way we can generate a magnetic field up to 700 Gauss in the region of the atoms. We will discuss in this presentation the state of the art of the experimental setup and control system to implement it. The measurement of the resonances is still missing in the literature for 23Na-41K.

Referências

1 CASTILHO, P. C. M. et al. A compact experimental machine for studying tunable Bose–Bose superfluid mixtures. Laser Physics Letters v.16, n.3, p.035501,2019.
2 CHIN, C. et al. Feshbach resonances in ultracold gases Reviews of Modern Physics, v.82, n.2, p.1225,2010.
3 CORDOVA, C. R. C. Quantum liquids droplets in a mixture of Bose-Einstein condensates. 2018.247p. (PhD thesis). - The Institute of Photonic Sciences; Universidad Politécnica de Cataluña, Barcelona,2018.