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Interactions in ultracold atomic systems: from the few- to the many-body problem

By bertuzzo - Posted on 26 fevereiro 2015

Dr. Manuel Valiente Cifuentes (Aarhus Univ, Denmark)
Terça-feira, 10 Março, 2015 - 11:00


Recent advances in the cooling, trapping, manipulation and control of neutral atomic systems make it possible to realise, or emulate some ideal models pertaining to condensed matter and high-energy physics in the laboratory. Space dimensionality can be effectively reduced via anisotropic trapping potentials, and low-energy interaction parameters can be tuned at will by means of magnetic Feshbach and confinement-induced resonances.  This great versatility has made it possible to even observe unambiguous signatures of the exotic few-body bound states predicted by Efimov over four decades ago. Moreover, orbital magnetism, with both Abelian and non-Abelian vector potentials, has already been implemented with cold atoms under carefully engineered laser fields. In the first part of the talk, I will review the experimental state-of-the-art with ultra cold atoms. I will then show how strong effective interactions in reduced-dimensional systems can be implemented [1] and how these can be used to engineer the spin dynamics in trapped one-dimensional few-body fermionic and spinor Bose systems [2]. In the second part of the talk, I will focus on the realisation of an interacting semiclassical gauge theory by taking advantage of weak particle-particle interactions and laser-matter coupling in a Bose gas [3]. If time allows for it, I will then move on to the non-Abelian case of Rashba spin-orbit coupling in a Fermi gas, and show how Fermi surface instabilities -- akin Pomeranchuk instabilities -- can occur due to the interplay of interactions and the non-Galilean nature of the system [4]. 

 [1] M. Valiente and K. Molmer, Phys. Rev. A 84, 053628 (2011).
 [2] A. G. Volosniev et al., Nature comms. 5:5300 (2014); Phys. Rev. A 91, 023620 (2015).
 [3] M. J. Edmonds, M. Valiente, G. Juzeliunas, L. Santos and P. Ohberg, Phys. Rev. Lett. 110, 085301 (2013).
 [4] D. Maldonado-Mundo, L. He, P. Ohberg and M. Valiente, Phys. Rev. A 88, 053609 (2013).