Sistema de Condensados de duas espécies: Sódio e Potássio

This new apparatus consists in a combination of two superfluids, Na and K, superposed in space. This experiment is quite challenge, but will permit the introduction a great deal of new ideas. In this system, vortex will be created in one of the species and controlling the inter-specie interaction. A knob that permits the control of turbulence can be created. Many other experiments concerning stabilization of high circulation vortices subjected to fluctuations on the interactions shall be done.

Our experimental system is a composition of three independent chambers, one for Na other for K, and both attached to a main chamber. In that chamber, we are going to produce a 3D MOT (Magneto optical trap) of Na and K atoms loaded from a 2D MOT for each specie [S. Donadello, M.Sc. thesis, University of Trento, 2012], using push beams.

To overcome the operation complexity of the former system, we have now a shorter system that has been attached to new system.

In Figure 1, we have a 3D drawing where on each side of the apparatus we produce the 2D MOTs and in the center, we have the main chamber that has been planned to have good optical access and accessibility to install coils to produce magnetic fields.

Figure 1: 3D vacuum system. On each side we have the chambers for the 2D Cooling and Trapping of Sodium and Potassium. On the middle, we have the science chamber where the condensation and studies will take place.

Figure 2 shows typical fluorescence images obtained from a 2D and 3D MOT.

Our time sequence starts on producing the 2D MOT of both species. The cold atoms is sent to the main chamber where the 3D MOTs take place. We monitor the fluorescence and optical absorption to obtain atomic number and density adequate to transfer the sample to a magnetic trap.

Figure 2: Typical Fluorescence from 2D and 3D MOT of Sodium atoms.

A pair of coils produces a quadruple type field for 3D MOT of both species, and as the current be ramped we transfer the atoms to a quadrupolar magnetic trap. Another pair of coils will produce magnetic field to tune interactions using Feshbach Resonances.

Afterwards those confined and cold sample will be transferred to an optical trap, where we will perform the experiments of formation of vortices and turbulence.

People involved:

  • Vanderlei Salvador Bagnato (Full Professor – IFSC/USP)
  • Kilvia M. Farias (Researcher – IFSC/USP)
  • Daniel Varela Magalhães (Professor-PI – EESC/USP)
  • Giacomo Roati (Professor – LENS – Florence, Italy)
  • Edwin E. Pedrozo-Peñafiel (PhD student – IFSC/USP)
  • Patricia C. Castilho (PhD student – IFSC/USP)
  • Emmanuel Mercado (PhD student – IFSC/USP)
  • Pedro Mazo (Undergratuate Student - IFSC/USP)
  • Pablo Santos Dias (Undergratuate Student - IFSC/USP)
  • Vitor Monteiro (Undergratuate Student - IFSC/USP)