Continuous wave near‐infrared atomic Xe laser excited by a radio frequency discharge in a slab geometry

Near‐infrared atomic Xe laser lines have been generated from an Ar:He:Xe laser gas mixture excited by a radio frequency (rf) discharge in a slab geometry. A maximum continuous wave (cw) output power of 1.5 W (270 W/l) was obtained at an rf frequency of 125 MHz from a gas mixture containing Ar:He:Xe (50:49:1) at a total gas pressure of 90 Torr

Crystalline ground state in chiral Gross-Neveu and Cooper pair models at finite densities

We study the possibility of spatially non-uniform ground state in (1+1)-dimensional models with quartic fermi interactions at finite fermion densities by introducing chemical potential \mu. We examine the chiral Gross-Neveu model and the Cooper pair model as toy models of the chiral symmetry breaking and the difermion pair condensates which are presumed to exist in QCD. We confirm in the chiral Gross-Neveu model that the ground state has a crystalline structure in which the chiral condensate oscillates in space with wave number 2\mu. Whereas in the Cooper pair model we find that the vacuum structure is spatially uniform. Some discussions are given to explain this difference.Comment: 18 pages, REVTeX, 3 eps figure