Novel Coexistence of Superconductivity with Two Distinct Magnetic Orders

Colorado State University, Fort Collins, Colorado, United States
Physical Review Letters (Impact Factor: 7.51). 12/2005; 95(21):217002. DOI: 10.1103/PhysRevLett.95.217002
Source: arXiv


The heavy fermion system exhibits properties that range from an incommensurate antiferromagnet for small to an exotic superconductor on the Ir-rich end of the phase diagram. At intermediate where antiferromagnetism coexists with superconductivity, two types of magnetic order are observed: the incommensurate one of and a new, commensurate antiferromagnetism that orders separately. The coexistence of -electron superconductivity with two distinct -electron magnetic orders is unique among unconventional superconductors, adding a new variety to the usual coexistence found in magnetic superconductors.

Download full-text


Available from: Jeffrey W. Lynn,
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The band structure, Fermi surface, and generalized susceptibility χ( q ) in the constant-matrix-element approximation for the heavy fermion series CeIn <sub>3</sub> , Ce M In <sub>5</sub>(M= Co,Rh,Ir), and PuCoGa <sub>5</sub> are studied by density functional calculations to address the relationship among superconductivity, magnetism, and Fermi surface nesting in these compounds. Within the scenario of magnetically mediated d wave superconductivity, our results indicate that the behavior of χ( q ) of the Ce class materials favors superconductivity if 4f electrons are treated as core states, since it exhibits broad plateaus with large magnitude around q =(0.5,0.5,0) and (0.5, 0.5, 0.5). In contrast, when the 5f electrons are treated as valence electrons, the χ( q ) of PuCoGa <sub>5</sub> exhibits a very sharp peak at q =(0.5,0.5,0) due to the strong nesting of hole and electron Fermi surface from the 16th and 17th bands. Not only the large spin fluctuation energy but also the strong nesting of Fermi surface in PuCoGa <sub>5</sub> may contribute to the much higher T<sub>c</sub> than that in the Ce series.
    Journal of Applied Physics 05/2006; 99(8-99):08M505 - 08M505-3. DOI:10.1063/1.2172549 · 2.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The magnetic structure and fluctuations of tetragonal GdRhIn5 were studied by resonant x-ray diffraction at the Gd LII and LIII edges, followed by a renormalization group analysis for this and other related Gd-based compounds, namely Gd2IrIn8 and GdIn3. These compounds are spin-only analogs of the isostructural Ce-based heavy-fermion superconductors. The ground state of GdRhIn5 shows a commensurate antiferromagnetic spin structure with propagation vector tau = (0,1/2, 1/2), corresponding to a parallel spin alignment along the a-direction and antiparallel alignment along b and c. A comparison between this magnetic structure and those of other members of the Rm(Co,Rh,Ir)n In3m+2n family (R =rare earth, n = 0, 1; m = 1, 2) indicates that, in general, tau is determined by a competition between first-(J1) and second-neighbor(J2) antiferromagnetic (AFM) interactions. While a large J1 /J2 ratio favors an antiparallel alignment along the three directions (the so-called G-AFM structure), a smaller ratio favors the magnetic structure of GdRhIn5 (C-AFM). In particular, it is inferred that the heavy-fermion superconductor CeRhIn5 is in a frontier between these two ground states, which may explain its non-collinear spiral magnetic structure. The critical behavior of GdRhIn5 close to the paramagnetic transition at TN = 39 K was also studied in detail. A typical second-order transition with the ordered magnetization critical parameter beta = 0.35 was experimentally found, and theoretically investigated by means of a renormalization group analysis. Comment: 22 pages, 4 figures
    Physical review. B, Condensed matter 07/2006; 74(21). DOI:10.1103/PhysRevB.74.214428 · 3.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cadmium doping the heavy-fermion superconductor CeCoIn(5) at the percent level acts as an electronic tuning agent, sensitively shifting the balance between superconductivity and antiferromagnetism and opening new ambient-pressure phase space in the study of heavy-fermion ground states.
    Physical Review Letters 09/2006; 97(5):056404. DOI:10.1103/PhysRevLett.97.056404 · 7.51 Impact Factor
Show more