The evidence for a Lifshitz point in MnP (invited)

Abstract

MnP has a triple point where paramagnetic, ferromagnetic, and helicoidal (fan) phases meet. The following features of this point agree with those expected for a Lifshitz point: the order of the various transitions near this point (first or second); the qualitative shapes of the phase boundaries; the crossover exponent φ obtained from the phase boundaries; the variation of the wave vector q↘ in the fan phase; the exponent βk derived from this variation; and dispersion curves for spin waves.