相关论文: Strong rejuvenation in a chiral-glass superconduct…
The temperature dependence of the magnetisation of a Cu(Mn) spin glass ($T_g$ $\approx$ 57 K) has been investigated using weak probing magnetic fields ($H$ = 0.5 or 0 Oe) and specific thermal protocols. The behaviour of the zero-field…
The present review is given on the paramagnetic Meissner effect observed in conventional and ceramic high-Tc superconductors. We discuss two mechanisms leading to this phenomenon: the d-wave and the flux compensation. It is shown that the…
The memory effect in a single crystal spin glass ($\mathrm{Cu}_{0.92}\mathrm{Mn}_{0.08}$) has been measured using \freq ac susceptibility techniques over a temperature range of $0.4 - 0.7 \, T_g$ and a model of the memory effect has been…
We have carried out a comprehensive investigation of magnetic properties of LuFe$_2$O$_4$, using AC susceptibility, DC magnetization and specific heat. A magnetic phase transition around $\sim$236 K was observed with DC magnetization and…
We have studied the slow dynamics of the ferromagnetic phases of the re-entrant CdCr_{2x}In_{2-2x}S_4 system for 0.85<x<=1 by means of low frequency ac susceptibility and magnetization measurements. Experimental procedures widely used in…
We have performed a large scale Monte Carlo simulation of a dilute classical Heisenberg model with ferromagnetic nearest neighbor and antiferromagnetic next-nearest neighbor interactions. We found that the model reproduces a reentrant…
The iron-based oxypnictide superconductor SmFeAsO0.8F0.2 was synthesized under high-pressure and investigated by measuring dc magnetic susceptibility. The zero-field cooled (ZFC) magnetic susceptibility confirmed the bulk superconductivity…
A spin glass is a diluted magnetic material in which the magnetic moments are randomly interacting, with a huge number of metastable states which prevent reaching equilibrium. Spin-glass models are conceptually simple, but require very…
We study numerically the nonequilibrium dynamics of the three-dimensional Heisenberg Edwards-Anderson spin glass submitted to protocols during which temperature is shifted or cycled within the spin glass phase. We show that (partial)…
A three-dimensional lattice of the Josephson junctions with a finite self-conductance is employed to model the ceramic superconductors. By Monte Carlo simulations it is shown that the chiral glass phase is stable in three dimensions even…
We present results of a Monte Carlo simulation of an Heisenberg Spin Glass model on a hipercubic cell of size 2 in {\it D} dimensions. Each spin interacts with {\it D} nearest neighbors and the lattice is expected to recover the completely…
New low frequency ac susceptibility measurements on two different spin glasses show that cooling/heating the sample at a constant rate yields an essentially reversible (but rate dependent) X(T) curve; a downward relaxation of X occurs…
We have compared aging phenomena in the Fe_{0.5}Mn_{0.5}TiO_3 Ising spin glass and in the CdCr_{1.7}In_{0.3}S_4 Heisenberg-like spin glass by means of low-frequency ac susceptibility measurements. At constant temperature, aging obeys the…
Superconductors are materials with zero electrical resistivity and the ability to expel magnetic fields known as the Meissner effect. Their dissipationless diamagnetic response is central to magnetic levitation and circuits such as quantum…
We compare aging in a disordered ferromagnet and in a spin glass, by studying the different phases of a reentrant system. We have measured the relaxation of the low-frequency ac susceptibility, in both the ferromagnetic and spin-glass…
A new iridium containing layered cuprate material, IrSr_2Sm_{1.15}Ce_{0.85}Cu_{2.175}O_{10, has been synthesized by conventional ambient-pressure solid-state techniques. The material's structure has been fully characterized by Rietveld…
Magneto-optical measurements in La${}_{0.8}$Sr${}_{0.2}$NiO${}_2$ and Nd${}_{0.825}$Sr${}_{0.175}$NiO${}_2$ reveal an intriguing new facet of infinite-layer nickelate superconductors: the onset of spin-glass behavior at a temperature far…
We study and discuss rejuvenation and memory (numerical) experiments in Ising and Heisenberg three and four dimensional spin glasses. We introduce a quantitative procedure to analyze the results of temperature cycling experiments. We also…
The isothermal remanent magnetization is used to investigate dynamical magnetic properties of spatially three dimensional spin glasses with different spin dimensionality (Ising, XY, Heisenberg). The isothermal remanent magnetization is…
We study aging phenomena of Migdal-Kadanoff spin glasses in order to clarify relevancy of temperature chaos to rejuvenation and memory. By exploiting renormalization, we do efficient dynamical simulations in very wide time/length scales…