Raman fingerprints on the Bloch sphere of a spinor Bose-Einstein condensate

• Published in: Journal of modern optics Vol. 63; no. 18; pp. 1759 - 1767
• Main Authors: Schultz, Justin T., Hansen, Azure, Murphree, Joseph D., Jayaseelan, Maitreyi, Bigelow, Nicholas P.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 10-10-2016; Taylor & Francis Ltd
• Subjects: Beams (radiation); Bloch sphere; Bose-Einstein condensates; Evolution; Mathematical models; Matter & antimatter; Optical properties; Optics; Phases; Raman interaction; spin textures; spin-1/2 system; Surface layer; Texture; Topology; Vortices
• ISSN: 0950-0340; 1362-3044
• DOI: 10.1080/09500340.2016.1139204

We explore the geometric interpretation of a diabatic, two-photon Raman process as a rotation on the Bloch sphere for a pseudo-spin-
system. The spin state of a spin-
quantum system can be described by a point on the surface of the Bloch sphere, and its evolution during a Raman pulse is a trajectory on the sphere determined by properties of the optical beams: the pulse area, the relative intensities and phases and the relative frequencies. We experimentally demonstrate key features of this model with a
Rb spinor Bose-Einstein condensate, which allows us to examine spatially dependent signatures of the Raman beams. The two-photon detuning allows us to precisely control the spin density and imprinted relative phase profiles, as we show with a coreless vortex. With this comprehensive understanding and intuitive geometric interpretation, we use the Raman process to create and tailor as well as study and characterize exotic topological spin textures in spinor BECs.