Incommensuratecommensurate transitions in the monoaxial chiral helimagnet driven by the magnetic field
Abstract
The zerotemperature phase diagram of the monoaxial chiral helimagnet in the magneticfield plane formed by the components parallel and perpendicular to the helical axis is thoroughly analyzed. The nature of the transition to the commensurate state depends on the angle between the field and the helical axis. For field directions close to the directions parallel or perpendicular to the helical axis the transition is continuous, while for intermediate angles the transition is discontinuous and the incommensurate and commensurate states coexist on the transition line. The continuous and discontinuous transition lines are separated by two tricritical points with specific singular behavior. The location of the continuous and discontinuous lines and of the tricritical points depend strongly on the easyplane anisotropy, the effect of which is analyzed. For high anisotropy the conical approximation locates the transition line very accurately, although it does not predict the continuous transitions and the tricritical behavior. It is shown that for high anisotropy, as in CrNb_{3}S_{6} , the form of the transition line is universal, that is, independent of the sample, and obeys a simple equation. The position of the tricritical points, which is not universal, is theoretically estimated for a sample of CrNb_{3}S_{6} .
 Publication:

Physical Review B
 Pub Date:
 April 2016
 DOI:
 10.1103/PhysRevB.93.134424
 arXiv:
 arXiv:1603.00755
 Bibcode:
 2016PhRvB..93m4424L
 Keywords:

 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 10 pages, 9 figures