1 / 8

Non-Equilibrium Dynamics in Ultracold Interacting Atoms

Non-Equilibrium Dynamics in Ultracold Interacting Atoms. Sergio Smith (Howard University). Simulations of Ultracold Atoms in Optical Lattices. I ntroduction. Ultracold atoms ( <1 μ K ) Cold enough to be trapped and studied Laser and evaporative cooling Bose-Einstein Condensates (BECs)

dayton
Download Presentation

Non-Equilibrium Dynamics in Ultracold Interacting Atoms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Non-Equilibrium Dynamics in Ultracold Interacting Atoms Sergio Smith (Howard University) Simulations of Ultracold Atoms in Optical Lattices

  2. Introduction • Ultracold atoms ( <1μK ) • Cold enough to be trapped and studied • Laser and evaporative cooling • Bose-Einstein Condensates (BECs) • Magnetic moment • Two-level system: spin up and spin down • Optical lattice • Grid of standing light waves • Potential wells at highest intensity locations

  3. Quantum effects • Quantized energy levels • Lowest energy state • Wave-particle duality • Tunneling E4 E3 E2 E1

  4. The Experiment • Two-dimensional lattice • Atoms loaded into wells • Two sub-lattices • Rubidum-87 atoms • Cool evaporatively • Become BECs • Potential lowered to allow tunneling • Measured quantity: Staggered Magnetization • Distribution of atoms on sub-lattices

  5. Simulation • Wave function • Single site ≈ Gaussian • Random initial phase • Some phase “memory” governed by α. • Many-body system • Sum of local functions • Disregard spatial evolution • Discretized Gross-Pitaevskii Equation

  6. Results J →J+δJ U=0.03J O= Experimental Data α=0.6 α=0.8 • Good qualitative agreement • Calculated value of J was wrong • Possibly due to screening effect

  7. Relevance and Future Research • Optical lattice experiments provide a highly tunable environment to study magnetism in BECs, with relevance to high-temperature superconductors. • Future research includes: • Fine-tuning J and α to fit experimental results • Studying what causes these discrepancies

  8. Acknowledgements • Dr. Michael Foss-Feig • Staff of Joint Quantum Institute (JQI) and Institute for Research in Electronics and Applied Physics (IRAEP) at the University of Maryland, College park.

More Related