title: Quantum Lifshitz Field Theory of a Frustrated Ferromagnet.
abstract: We propose a universal nonlinear sigma model field theory for one-dimensional frustrated ferromagnets, which applies in the vicinity of a "quantum Lifshitz point," at which the ferromagnetic state develops a spin wave instability. We investigate the phase diagram resulting from perturbations of the exchange and of magnetic field away from the Lifshitz point, and uncover a rich structure with two distinct regimes of different properties, depending upon the value of a marginal, dimensionless, parameter of the theory. In the regime relevant for one-dimensional systems with low spin, we find a metamagnetic transition line to a vector chiral phase. This line terminates in a critical end point, beyond which there is at least one multipolar or "spin nematic" phase. We show that the field theory is asymptotically exactly soluble near the Lifshitz point.
authors.affiliation: Kavli Institute of Theoretical Physics, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: Leon
authors.initials: L
authors.lastname: Balents
authors.affiliation: Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Starykh