Cherng, R. W.Gritsev, V.Stamper-Kurn, D. M.Demler, Eugene2016-08-242008Cherng, R. W., V. Gritsev, D. M. Stamper-Kurn, and E. Demler. 2008. “ Dynamical Instability of the XY Spiral State of Ferromagnetic Condensates .” Physical Review Letters 100 (18) (May 7). doi:10.1103/physrevlett.100.180404.0031-9007http://nrs.harvard.edu/urn-3:HUL.InstRepos:27889191We calculate the spectrum of collective excitations of the XY spiral state prepared adiabatically or suddenly from a uniform ferromagnetic F ! 1 condensate. For spiral wave vectors past a critical value, spin wave excitation energies become imaginary indicating a dynamical instability. We construct phase diagrams as functions of spiral wave vector and quadratic Zeeman energy.en-USJournal Article2016-08-2410.1103/PhysRevLett.100.180404