We study the ferromagnetic criticality of the pyrochlore magnet Lu2 V2 O7 at the ferromagnetic transition TC% 70 K from the isotherms of magnetization MeHT via an iteration process and the Kouvel-Fisher method. The cr...We study the ferromagnetic criticality of the pyrochlore magnet Lu2 V2 O7 at the ferromagnetic transition TC% 70 K from the isotherms of magnetization MeHT via an iteration process and the Kouvel-Fisher method. The critical exponents associated with the transition are determined: b = 0.32(1), c = 1.41(1),and d ? 5:38. The validity of these critical exponents is further verified by scaling all the MeHT data in the vicinity of TConto two universal curves in the plot of M=jejbversus H=jejbtc, where e ? T=TCà 1.The obtained b and c values show asymmetric behaviors on the T < TCand the T > TCsides, and are consistent with the predicted values of 3 D Ising and cubic universality classes, respectively. This makes Lu2 V2 O7 a rare example in which the critical behaviors associated with a ferromagnetic transition belong to different universality classes. We describe the observed criticality from the Ginzburg-Landau theory with the quartic cubic anisotropy that microscopically originates from the anti-symmetric Dzyaloshinskii-Moriya interaction as revealed by recent magnon thermal Hall effect and theoretical investigations.展开更多
基金supported by the National Key R&D Program of China (2018YFA0305700, 2018YFA0305800, 2016YFA0301001 and 2016YFA0300500)the National Natural Science Foundation of China (11574377, 11834016, 11874400)+3 种基金the Strategic Priority Research Program,Key Research Program of Frontier Sciences of the Chinese Academy of Sciences (XDB25000000, XDB07020100 and QYZDB-SSW-SLH013)supported by NSF DMR 1350002. J.P.S.support from the China Postdoctoral Science Foundationthe Postdoctoral Innovative Talent Program
文摘We study the ferromagnetic criticality of the pyrochlore magnet Lu2 V2 O7 at the ferromagnetic transition TC% 70 K from the isotherms of magnetization MeHT via an iteration process and the Kouvel-Fisher method. The critical exponents associated with the transition are determined: b = 0.32(1), c = 1.41(1),and d ? 5:38. The validity of these critical exponents is further verified by scaling all the MeHT data in the vicinity of TConto two universal curves in the plot of M=jejbversus H=jejbtc, where e ? T=TCà 1.The obtained b and c values show asymmetric behaviors on the T < TCand the T > TCsides, and are consistent with the predicted values of 3 D Ising and cubic universality classes, respectively. This makes Lu2 V2 O7 a rare example in which the critical behaviors associated with a ferromagnetic transition belong to different universality classes. We describe the observed criticality from the Ginzburg-Landau theory with the quartic cubic anisotropy that microscopically originates from the anti-symmetric Dzyaloshinskii-Moriya interaction as revealed by recent magnon thermal Hall effect and theoretical investigations.
