相关论文: Spin-flop transitions and spin-wave gaps in La_2Cu…
We investigate the occurrence of a two-step spin-flop transition and spin reorientation when a longitudinal magnetic field is applied to lightly hole-doped La(2)CuO(4). We find that for large and strongly frustrating impurities, such as Sr…
While the dominant magnetic interaction in La$_2$CuO$_4$ is superexchange between nearest-neighbor Cu moments, the pinning of the spin direction depends on weak anisotropic effects associated with spin-orbit coupling. The symmetry of the…
The effects of quantum fluctuations on the magnetic field dependence of the spin-wave gaps in the lamellar antiferromagnet La$_2$CuO$_4$ are considered. Nonlinear corrections to the spin-wave spectrum are calculated to leading order in 1/S,…
An effective field theory is derived that describes the low-frequency spin dynamics in the low-temperature orthorombic phase of La_2CuO_4. Restricted to a single CuO_2 layer the effective theory is a simple generalization of the…
We report thermodynamic, neutron diffraction, and inelastic neutron scattering measurements on Cs$_2$RuO$_4$, a member of the celebrated family of frustrated magnets Cs$_2$MX$_4$ (M = Cu, Co, X = Br, Cl). Unlike the previously studied…
The magnetization in a lightly doped La$_{2-x}$Sr$_x$CuO$_4$ ($x=0.018$) single crystal was measured. Spin-flop transition was clearly observed in the hole doped antiferromagnetically ordered state under increasing magnetic fields…
In this paper we compute the mean field phase diagram of a doped antiferromagnet, in a magnetic field and with anisotropic exchange. We show that at zero temperature there is a metamagnetic transition from the antiferromagnetic…
The magnetic properties of CaCo$_{2}$As$_{2}$ single crystal was systematically studied by using dc magnetization and magnetic torque measurements. A paramagnetic to antiferromagnetic transition occurs at $T_N$ = 74 K with Co spins being…
The classical spin-flop is the field-driven first-order reorientation transition in easy-axis antiferromagnets. A comprehensive phenomenological theory of easy-axis antiferromagnets displaying spin-flops is developed. It is shown how the…
We discuss theoretically rather rear example of spin-flop transition which is accompanied with changing the type of magnetic ordering and which seemingly has not been addressed yet. We demonstrate that changing the type of magnetic ordering…
We show that, contrary to previous belief, the transition to the antiferromagnetic state of Sr$_2$IrO$_4$ in zero magnetic field does show up in the transverse resistivity. We attribute this to a change in transverse integrals associated to…
The in-plane magnetic field penetration depth (\lambda_{ab}) in single-crystal La_{1.83}Sr_{0.17}CuO_4 was investigated by means of the muon-spin rotation (\muSR) technique. The temperature dependence of \lambda^{-2}_{ab} has an inflection…
We characterize the phase space for the infinite volume limit of a ferromagnetic mean-field XY model in a random field pointing in one direction with two symmetric values. We determine the stationary solutions and detect possible phase…
The weak ferromagnetism present in insulating La_{2}CuO_4 at low doping leads to a spin flop transition, and to transverse (interplane) hopping of holes in a strong external magnetic field. This results in a dimensional crossover 2D $\to$…
Neutron diffraction was used to determine the crystal structure and magnetic ordering pattern of a La2CuO4 single crystal, with and without applied magnetic field. A previously unreported, subtle monoclinic distortion of the crystal…
$\beta$-TeVO$_4$ is a frustrated spin 1/2 zig-zag chain system,where spin-density-wave (SDW), vector chiral (VC)and an exotic dynamic spin-stripe phase compete at low temperatures. Here we use torque magnetometry to study the anisotropy of…
A magnetic susceptibility which decreases with decreasing temperature is observed in all $CuO_2$ based superconductors with less than optimal doping. We propose that in $La_{2-x} Sr_x CuO_4$ this is due to antiferromagnetic ordering which…
A comprehensive theoretical investigation on the field-driven reorientation transitions in uniaxial multilayers with antiferromagnetic coupling is presented. It is based on a complete survey of the one-dimensional solutions for the basic…
Two-stage spin-flop transitions are observed the in quasi-one-dimensional antiferromagnet, BaCu${}_2$Si${}_2$O${}_7$. A magnetic field applied along the easy axis induces a spin-flop transition at 2.0 T followed by a second transition at…
Identifying the nature of a spin-flop (SFO) transition, first- or second-order (FO or SO), remains a major challenge in condensed-matter physics due to the technically undistinguishable effect of misalignment between applied-field direction…