Resonances in a dilute gas of magnons and metamagnetism of isotropic frustrated ferromagnetic spin chains

MARCELO ARLEGO; FABIAN HEIDRICH-MEISNER; ANDREAS HONECKER; GERARDO ROSSINI; TEIMURAZ VEKUA

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2011 vol. 84 p. 224409 - 22440920

1098-0121

We show that spin-S chains with SU(2)-symmetric, ferromagnetic nearest-neighbor and frustrating antiferromagnetic next-nearest-neighbor exchange interactions exhibit metamagnetic behavior under the influence of an external magnetic field for small S, in the form of a first-order transition to the fully polarized state. The corresponding magnetization jump increases gradually starting from an S-dependent critical value of exchange couplings and takes a maximum in the vicinity of a ferromagnetic Lifshitz point. The metamagnetism results from resonances in the dilute magnon gas caused by an interplay between quantum fluctuations and frustration.