Time-resolved probing of the ground state coherence in rubidium

Time-resolved probing of the ground state coherence in rubidium.

We demonstrate the preparation and probing of the coherence between the hyperfine ground states |S(1/2),F=1> and |5S(1/2),F=2> of the Rb87 isotope. The effects of various coherence control techniques, i.e., fractional stimulated Raman adiabatic passage and coherent population return, on the coherence are investigated. These techniques are implemented using nearly degenerate pump and Stokes lase...

Ground-state properties of magnetically trapped Bose-condensed rubidium gas.

We give a quantitative account of the ground-state properties of the dilute magnetically trapped 87Rb gas recently cooled and Bose-Einstein condensed at nanokelvin-scale temperatures. Using simple scaling arguments, we show that at large particle number the kinetic energy is a small perturbation, and find a spatial structure of the cloud of atoms and its momentum distribution dependent in an es...

Probing quantum frustrated systems via factorization of the ground state.

The existence of definite orders in frustrated quantum systems is related rigorously to the occurrence of fully factorized ground states below a threshold value of the frustration. Ground-state separability thus provides a natural measure of frustration: strongly frustrated systems are those that cannot accommodate for classical-like solutions. The exact form of the factorized ground states and...

critical period effects in foreign language learning:the influence of maturational state on the acquisition of reading,writing, and grammar in english as a foreign language

since the 1960s the age effects on learning both first and second language have been explored by many linguists and applied linguists (e.g lennerberg, 1967; schachter, 1996; long, 1990) and the existence of critical period for language acquisition was found to be a common ground of all these studies. in spite of some common findings, some issues about the impacts of age on acquiring a second or...

Mapping the evolution of spatial coherence through time-resolved fluorescence