title: Spin dynamics in a one-dimensional ferromagnetic bose gas.
abstract: We investigate the propagation of spin excitations in a one-dimensional ferromagnetic Bose gas. While the spectrum of longitudinal spin waves in this system is soundlike, the dispersion of transverse spin excitations is quadratic, making a direct application of the Luttinger liquid theory impossible. By using a combination of different analytic methods we derive the large time asymptotic behavior of the spin-spin dynamical correlation function for strong interparticle repulsion. The result has an unusual structure associated with a crossover from the regime of trapped spin wave to an open regime and does not have analogues in known low-energy universality classes of quantum 1D systems.
authors.affiliation: DPMC-MaNEP, University of Geneva, 24 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: M B
authors.initials: MB
authors.lastname: Zvonarev
authors.forename: V V
authors.initials: VV
authors.lastname: Cheianov
authors.forename: T
authors.initials: T
authors.lastname: Giamarchi