Electron Spin Resonance was used to study the spin-dimer compound β-Sr2Cu(BO3)2. The value of the antiferromagnetic coupling constant (J) between the copper dimers was estimated from temperature-dependence measurements to be 92 K at a frequency of 111.3 GHz and 91 K at a frequency of 66.7 GHz. Introduction From refrigerator magnets to hard drives, magnetism is a familiar phenomenon. The source ...

We present a detailed study of the low temperature and high magnetic field phases in the chemical substitution series URu2Si2−xPx using electrical transport and magnetization in pulsed magnetic fields up to 65T. Within the hidden order region (0 < x < 0.035) the high field ordering is robust even as the hidden order temperature is suppressed. Earlier work shows that for 0.035 < x < 0.26 there i...

Using model calculations of a disordered d-wave superconductor with on-site Hubbard repulsion, we show how dopant disorder can stabilize novel states with antiferromagnetic order. We find that the critical strength of correlations or impurity potential necessary to create an ordered magnetic state in the presence of finite disorder is reduced compared to that required to create a single isolate...

A magnetic origin for the honeycomb reconstruction of metallic surfaces with three-fold symmetry like Pb/Ge (111) is proposed. Assuming that the groundstate is an antiferromagnet insulator over the triangular lattice of adatom sites (Pb), we demonstrate that the former is simultaneously unstable to canting and to a structural distortion if the surface is soft enough. We therefore predict a net ...

Many physical properties of high-temperature superconductors are two-dimensional phenomena derived from their square-planar CuO2 building blocks. This is especially true of the magnetism from the copper ions. As mobile charge carriers enter the CuO2 layers, the antiferromagnetism of the parent insulators, where each copper spin is antiparallel to its nearest neighbours, evolves into a fluctuati...

Using first-principles calculations, we investigate the geometric structures and electronic properties of porous silicene and germanene nanosheets, which are the Si and Ge analogues of α-graphyne (referred to as silicyne and germanyne). It is found that the elemental silicyne and germanyne sheets are energetically unfavourable. However, after the C-substitution, the hybrid graphyne-like sheets ...

We report low-temperature and high-pressure measurements of the electrical resistivity T of the antiferromagnetic compound NiS2 in its high-pressure metallic state. The form of T , p suggests the presence of a quantum phase transition at a critical pressure pc=76 5 kbar. Near pc, the temperature variation of T is similar to that observed in NiS2−xSex near the critical composition x=1, where met...

We investigate the competition between antiferromagnetism and triplet superconductivity in quasi-onedimensional electron systems. We show that the two order parameters can be unified using a SO(4) symmetry and demonstrate the existence of such symmetry in one-dimensional Luttinger liquids of interacting electrons. We argue that approximate SO(4) symmetry remains valid even when interchain hoppi...