TY - JOUR
T1 - Ginzburg-Landau theory for the conical cycloid state in multiferroics
T2 - Applications to CoCr2O4
AU - Zhang, Chuanwei
AU - Tewari, Sumanta
AU - Toner, John
AU - Das Sarma, S.
PY - 2008/10/30
Y1 - 2008/10/30
N2 - We show that the cycloidal magnetic order of a multiferroic can arise in the absence of spin and lattice anisotropies, e.g., in a cubic material, and this explains the occurrence of such a state in CoCr2O4. We discuss the case when this order coexists with ferromagnetism in a so-called "conical cycloid" state and show that a direct transition to this state from the ferromagnet is necessarily first order. On quite general grounds, the reversal of the direction of the uniform magnetization in this state can lead to the reversal of the electric polarization as well without the need to invoke "toroidal moment" as the order parameter.
AB - We show that the cycloidal magnetic order of a multiferroic can arise in the absence of spin and lattice anisotropies, e.g., in a cubic material, and this explains the occurrence of such a state in CoCr2O4. We discuss the case when this order coexists with ferromagnetism in a so-called "conical cycloid" state and show that a direct transition to this state from the ferromagnet is necessarily first order. On quite general grounds, the reversal of the direction of the uniform magnetization in this state can lead to the reversal of the electric polarization as well without the need to invoke "toroidal moment" as the order parameter.
UR - https://www.scopus.com/pages/publications/55349141825
U2 - 10.1103/PhysRevB.78.144426
DO - 10.1103/PhysRevB.78.144426
M3 - Article
AN - SCOPUS:55349141825
SN - 1098-0121
VL - 78
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 14
M1 - 144426
ER -