We investigate the quantum phase transition of itinerant electrons from a paramagnet to a state which displays long-period helical structures due to a Dzyaloshinskii instability of the ferromagnetic state. In particular, we study how the self-generated effective long-range interaction recently identified in itinerant quantum ferromagnets is cut off by the helical ordering. We find that for a sufficiently strong Dzyaloshinskii instability the helimagnetic quantum phase transition is of second order with mean-field exponents. In contrast, for a weak Dzyaloshinskii instability the transition is analogous to that in itinerant quantum ferromagnets, i.e., it is of first order, as has been observed in MnSi.
T. Vojta and R. Sknepnek, "Quantum Phase Transition of Itinerant Helimagnets," Physical Review B - Condensed Matter and Materials Physics, vol. 64, no. 5, pp. 524041-524044, American Physical Society (APS), Aug 2001.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevB.64.052404
Keywords and Phrases
electron; magnet; magnetic field; mathematical analysis; phase transition; quantum mechanics
International Standard Serial Number (ISSN)
Article - Journal
© 2001 American Physical Society (APS), All rights reserved.