James F. Annett

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We have investigated the superconducting state of the noncentrosymmetric compound Re6Zr using magnetization, heat capacity, and muon-spin relaxation or rotation (μSR) measurements. Re6Zr has a superconducting transition temperature, Tc=6.75±0.05  K. Transverse-field μSR experiments, used to probe the superfluid density, suggest an s-wave character for the(More)
The structural properties of three-dimensional ordered phases of C3B and C5B compounds were studied using the ab initio pseudopotential method. Two different stacking sequences, BC and BB, of graphite layers were considered. Results indicate that for C3B, the structure with hexagonally symmetric distribution of B atoms and BC stacking is stable, whereas for(More)
Muon spin rotation and relaxation experiments on the centrosymmetric intermetallic superconductor LaNiGa2 are reported. The appearance of spontaneous magnetic fields coincides with the onset of superconductivity, implying that the superconducting state breaks time reversal symmetry, similarly to noncentrosymmetric LaNiC2. Only four triplet states are(More)
The nature of the pairing states of superconducting LaNiC_{2} and LaNiGa_{2} has to date remained a puzzling question. Broken time reversal symmetry has been observed in both compounds and a group theoretical analysis implies a nonunitary triplet pairing state. However, all the allowed nonunitary triplet states have nodal gap functions but most(More)
We present an analysis of the Hall conductivity σ(xy)(ω,T) in time reversal symmetry breaking states of exotic superconductors. We find that the dichroic signal is nonzero in systems with interband order parameters. This new intrinsic mechanism may explain the Kerr effect observed in strontium ruthenate and possibly other superconductors. We predict(More)
The atom in jellium model describes a single atom interacting with an infinite homogenous electron gas. It can be thought of as the simplest first principles model which includes all of the essential physics of the Anderson impurity model, namely one or more localized atomiclike states hybridized with a continuum of free electron band states. For example in(More)
The December issue of the Psi-k Newsletter carried the sad news of the death on October 25, 2012 of Professor Balazs L. Gyorffy, together with a reprint of a formal obituary that was written by Professor Robert Evans, FRS. As part of a broader tribute to Professor Gyorffy, this issue carries a compilation of contributions from some of Balazs’ collaborators,(More)
We develop a method to solve the Bogoliubov de Gennes equation for superconductors self-consistently, using the recursion method. The method allows the pairing interaction to be either local or non-local corresponding to s and d–wave superconductivity, respectively. Using this method we examine the properties of various S − I −N and D − I −N interfaces. In(More)
The presence of a spin-flip potential at the interface between a superconductor and a ferromagnetic metal allows for the generation of equal-spin spin-triplet Cooper pairs. These Cooper pairs are compatible with the exchange interaction within the ferromagnetic region and hence allow for the long-range proximity effect through a ferromagnet or half-metal.(More)