Related papers: Incommensurate magnetic order and dynamics induced…
The influence of magnetic (S=1) and nonmagnetic (S=0) impurities on the spin dynamics of an optimally doped high temperature superconductor is compared in two samples with almost identical superconducting transition temperatures:…
We study magnetic order induced by non-magnetic impurities in quantum paramagnets with incommensurate host spin correlations. In contrast to the well-studied commensurate case where the defect-induced magnetism is spatially disordered but…
Using neutron scattering techniques, we have studied incommensurate spin ordering as well as low energy spin dynamics in single crystal underdoped \LBCO with x$\sim$0.095 and 0.08; high temperature superconductors with T$_C \sim$ 27 K and…
Effects of the magnetic impurity Ni on the Cu-spin dynamics and superconductivity have been studied in La_2-x_Sr_x_Cu_1-y_Ni_y_O_4_ with x = 0.13 changing y finely up to 0.10. Compared with the case of the nonmagnetic impurity Zn, it has…
A comprehensive inelastic neutron scattering study of magnetic excitations in the near-optimally doped high-temperature superconductor ${\rm YBa_{2}Cu_{3}O_{6.85}}$ is presented. The spin correlations in the normal state are commensurate…
We present a neutron-scattering study of the static and dynamic spin correlations in the underdoped high-temperature superconductor YBa(2)Cu(3)O(6.45) in magnetic fields up to 15 T. The field strongly enhances static incommensurate magnetic…
We study the effect of non-magnetic Zn$^{2+}$ (spin-$0$) and magnetic Ni$^{2+}$ (spin-$1$) impurities on the ground state and low-lying excitations of the quasi-one-dimensional spin-$1/2$ Heisenberg antiferromagnet Sr$_{2}$CuO$_{3}$ using…
We report muon-spin rotation and neutron-scattering experiments on non-magnetic Zn impurity effects on the static spin-stripe order and superconductivity of the La214 cuprates. Remarkably, it was found that, for samples with hole doping x =…
We present muon spin relaxation (muSR) measurements on a large YBa2Cu3O6.6 single crystal in which two kinds of unusual magnetic order have been detected in the pseudogap region by neutron scattering. A comparison is made to measurements on…
Both Zn-doping and $c$-axis magnetic fields have been observed to increase the spin stripe order in La$_{2-x}$Ba$_x$CuO$_4$ with $x$ close to 1/8. For $x=0.095$, the applied magnetic field also causes superconducting layers to decouple,…
The magnetic excitation spectrum of a YBa_2 Cu_3 O_7 crystal containing 0.5% of nonmagnetic (Zn) impurities has been determined by inelastic neutron scattering. Whereas in the pure system a sharp resonance peak at E ~ 40 meV is observed…
We studied low-frequency spin dynamics near the impurity-induced superconductor-to-insulator transition for underdoped high-Tc superconductor YBa2(Cu1-xMx)4O8 (M=Ni, Zn) using the Cu nuclear quadrupole resonance (NQR) spin-echo technique.…
Zero-field muon-spin-relaxation (muSR) and magnetic-susceptibility measurements have been carried out in La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_ with x = 0.10, 0.115 and 0.13 changing the Zn-concentration y finely up to 0.10, with the aim to clarify…
We use inelastic neutron scattering to demonstrate that at low temperatures, the low frequency magnetic fluctuations in YBa_2Cu_3O_{6.6} ($T_c=62.7$ K) are incommensurate, being found at positions displaced by $\pm\delta$ ($0.057\pm 0.006$…
We study the effects of Cu substitution in Fe1.1Te, the non-superconducting parent compound of the iron-based superconductor, Fe1+yTe1-xSex, utilizing neutron scattering techniques. It is found that the structural and magnetic transitions,…
Nonmagnetic Zn impurities are known to strongly suppress superconductivity. We review their effects on the spin excitation spectrum in $\rm YBa_2Cu_3O_{7}$, as investigated by inelastic neutron scattering measurements.
Electronic charges introduced in copper-oxide planes generate high-transition temperature superconductivity but, under special circumstances, they can also order into filaments called stripes. Whether an underlying tendency of charges to…
We use inelastic neutron scattering to study the temperature dependence of the spin excitations of a detwinned superconducting YBa$_2$Cu$_3$O$_{6.45}$ ($T_c=48$ K). In contrast to earlier work on YBa$_2$Cu$_3$O$_{6.5}$ ($T_c=58$ K), where…
High pressure neutron diffraction is employed to investigate the magnetic behavior of CaMn$_2$Bi$_2$ in extreme conditions. In contrast to antiferromagnetic ordering on Mn atoms reported at ambient pressure, our results reveal that at high…
We present a theory of magnetic (S=1) Ni and nonmagnetic Zn impurities in underdoped cuprates. Both types of impurities are shown to induce S=1/2 moments on Cu sites in the proximity of the impurity, a process which is intimately related to…