Helical glasses near ferromagnetic quantum criticality


We study the effects of quenched charge disorder on the phase reconstruction near itinerant ferromagnetic quantum critical points in three spatial dimensions. Combining a Replica-disorder average with a fermionic version of the quantum order-by-disorder mechanism, we show that weak disorder destabilizes the ferromagnetic state and enhances the susceptibility towards incommensurate, spiral magnetic ordering. The Goldstone modes of the spiral phase are governed by a 3d-XY model. The induced disorder in the pitch of the spiral generates a random anisotropy for the Goldstone modes, inducing vortex lines in the phase of the helical order and rendering the magnetic correlations short ranged with a strongly anisotropic correlation length.

In Phys. Rev. B 87, 224203 (2013)
Dr Steven J. Thomson
Dr Steven J. Thomson
Marie Skłodowska-Curie Research Fellow in Theoretical Condensed Matter Physics

Theoretical condensed matter physicist, currently a Marie Skłodowska-Curie Research Fellow at Freie Universität Berlin.