Heavy fermion materials gain high electronic masses and expand Fermi surfaces when the high-temperature localized f electrons become itinerant and hybridize with the conduction band at low temperatures. However, despite the common application of this model, direct microscopic verification remains lacking. Here we report high-resolution angle-resolved photoemission spec-1 arXiv:1610.06724v1 [cond-mat.str-el]

We report the thermodynamic and muon spin relaxation (µSR) evidences for a possible gapless spin liquid in Tm3Sb3Zn2O14, with the rare-earth ions Tm 3+ forming a two-dimensional kagomé lattice. We extract the magnetic specific heat of Tm3Sb3Zn2O14 by subtracting the phonon contribution of the non-magnetic isostructural material La3Sb3Zn2O14 and obtain a clear linear-T temperature dependence of magnetic specific heat at low temperatures. No long-range magnetic order was observed down to 0.35 K in the heat capacity measurements, and no signature of spin freezing down to 50 mK was observed in A.C. susceptibility measurements. The absence of magnetic order is further confirmed by the µSR measurements down to 20 mK. We find that the spinlattice relaxation time remains constant down to the lowest temperature. We point out that the physics in Tm3Sb3Zn2O14 is fundamentally different from the Cu-based herbertsmithite and propose spin liquid ground states with non-Kramers doublets on the kagomé lattice to account for the experimental results. However, we can not rule out that these exotic properties are induced by the Tm/Zn site-mixing disorder in Tm3Sb3Zn2O14.

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We report results of a muon spin relaxation (µSR) study of YFe 2 Al 10 , a quasi-2D nearlyferromagnetic metal in which unconventional quantum critical behavior is observed. No static Fe 2+ magnetism, with or without long-range order, is found down to 19 mK. The dynamic muon spin relaxation rate λ exhibits power-law divergences in temperature and magnetic field, the latter for fields that are too weak to affect the electronic spin dynamics directly. We attribute this to the proportionality of λ(ω µ , T ) to the dynamic structure factor S(ω µ , T ), where ω µ ≈ 10 5 -10 7 s −1 is the muon Zeeman frequency. These results suggest critical divergences of S(ω µ , T ) in both temperature and frequency. Power-law scaling and a 2D dissipative quantum XY (2D-DQXY) model both yield forms for S(ω, T ) that agree with neutron scattering data (ω ≈ 10 12 s −1 ). Extrapolation to µSR frequencies agrees semi-quantitatively with the observed temperature dependence of λ(ω µ , T ), but predicts frequency independence for ω µ ≪ T in extreme disagreement with experiment. We conclude that the quantum critical spin dynamics of YFe 2 Al 10 are not well understood at low frequencies.

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Combining with a large number of concrete test and the moving reconstruction project of Qingyang petrochemical about three million tons, by adjusting “advance maintenance time”, monitor and research on the construction quality of mixed composite pumping antifreeze ordinary concrete in winter. Then provide reference and theoretical basis for construction of this winter antifreeze mixed composite pumping concrete.

Topological superconductivity is an exotic phenomenon due to the symmetry-protected topological surface state, in which a quantum system has an energy gap in the bulk but supports gapless excitations conned to its boundary. Symmetries including central and time-reversal, along with their relations with topology, are crucial for topological superconductivity. We report muon spin relaxation/rotation (μSR) experiments on a topological noncentrosymmetric superconductor PbTaSe2 to study its TRS and gap symmetry. Zero-field μSR experiments indicate the absence of internal magnetic eld in the superconducting state, consistent with previous μSR results. Furthermore, transverse-field μSR measurements reveals that the superconducting gap of PbTaSe2 is an isotropic three-dimensional fully-gapped single-band. The fully-gapped results can help understand the pairing mechanism and further classify the topological superconductivity in this system.