ABSTRACT
The Redfield master equation was solved analytically for a nuclear system with spin I=7/2. Using the irreducible tensor operator basis, the solutions of each density matrix element were computed. The experimental setup consisted of the 133Cs nuclei of the cesium-pentadecafluorooctanoate molecule in a lyotropic liquid crystal sample in the nematic phase at room temperature. Experimental longitudinal and transverse magnetization dynamics of the 133Cs nuclei were monitored, and the theoretical approach was used to generate valuable mathematical expressions with the highest accuracy through numerical procedures. This methodology can be extended to other nuclei with minimal difficulties.
ABSTRACT
We have produced and characterized spin-squeezed states at a temperature of 26 °C in a nuclear magnetic resonance quadrupolar system. The experiment was carried out on 133Cs nuclei of spin I=7/2 in a sample of lyotropic liquid crystal. The source of spin squeezing was identified as the interaction between the quadrupole moment of the nuclei and the electric field gradients present within the molecules. We use the spin angular momentum representation to describe formally the nonlinear operators that produce the spin squeezing on a Hilbert space of dimension 2I+1=8. The quantitative and qualitative characterization of this spin-squeezing phenomenon is expressed by a squeezing parameter and squeezing angle developed for the two-mode Bose-Einstein condensate system, as well as by the Wigner quasiprobability distribution function. The generality of the present experimental scheme points to potential applications in solid-state physics.
