Hysteresis and Anisotropic Magnetoresistance in Antiferromagnetic $Nd_{2-x}Ce_xCuO_{4}$

摘要

The out-of-plane resistivity ($\rho_c$) and magnetoresistivity (MR) arestudied in antiferromangetic (AF) $Nd_{2-x}Ce_xCuO_{4}$ single crystals, whichhave three types of noncollinear antiferromangetic spin structures. Theapparent signatures are observed in $\rho_c(T)$ measured at the zero-field and14 T at the spin structure transitions, giving a definite evidence for theitinerant electrons directly coupled to the localized spins. One of strikingfeature is an anisotropy of the MR with a fourfold symmetry upon rotating theexternal field (B) within ab plane in the different phases, while twofoldsymmetry at spin reorientation transition temperatures. The intriguing thermalhysteresis in $\rho_c(T,B)$ and magnetic hysteresis in MR are observed at spinreorientation transition temperatures.