2014/03/11 by R. Auccaise, A. G. Araujo-Ferreira, R. S. Sarthour +3 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.114.043604
arxiv created 2014/03/11 · arxiv updated 2015/06/19
We have characterized spin-squeezed states produced at a temperature of 26^∘\mathrm C on a Nuclear Magnetic Resonance (NMR) quadrupolar system. The implementation is carried out in an ensemble of 133Cs nuclei with spin I=7/2 of a lyotropic liquid crystal sample. We identify the source of spin squeezing due to the interaction between the quadrupole moment of the nuclei and the electric field gradients internally present in the molecules. We use the spin angular momentum representation to describe formally the nonlinear operators that produce the spin squeezing. The quantitative and qualitatively characterization of the spin squeezing phenomena is performed through a squeezing parameter and squeezing angle developed for the two-mode BEC system, and, as well, by the Wigner quasi-probability distribution function. The generality of the present experimental scheme indicates its potential applications on solid state physics.