Publications (8)7.37 Total impact
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Article: Local magnetic susceptibility of the positive muon in the quasi-one-dimensional S=1/2 antiferromagnet dichlorobis (pyridine) copper (II).
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ABSTRACT: We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi-one-dimensional spin 1/2 antiferromagnet dichlorobis (pyridine) copper (II). Signals from three distinct sites are resolved and have a temperature dependent frequency shift which is significantly different than the magnetic susceptibility. This difference is attributed to a muon induced perturbation of the spin 1/2 chain. The obtained frequency shifts are compared with transfer matrix density-matrix renormalization-group numerical simulations.Physical Review Letters 08/2003; 91(2):027202. · 7.37 Impact Factor -
Article: Physica B32 (2WYY 42 --42
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ABSTRACT: We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi-one-dimensional spin1/2 antiferromagnet KCuF 3 : Signals from two distinct sites are resolved which have a temperature-dependent frequency shift which is different than the magnetic susceptibility. This difference is attributed to a muon-induced perturbation of the spin1/2 chain.03/2003; -
Article: Local Magnetic Susceptibility of the Positive Muon in the Quasi 1D S=1/2 Antiferromagnet dichlorobis (pyridine) copper (II)
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ABSTRACT: We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi one-dimensional spin 1/2 antiferromagnet dichlorobis (pyridine) copper (II). Signals from three distinct sites are resolved and have a temperature dependent frequency shift which is significantly different than the magnetic susceptibility. This difference is attributed to a muon induced perturbation of the spin 1/2 chain. The obtained frequency shifts are compared with Transfer Matrix DMRG numerical simulations. Comment: 3 pages 3 figures, submitted to PRL01/2003; -
Article: Local Magnetic Susceptibility of the Positive Muon in the Quasi 1D S=1/2 Antiferromagnet KCuF$_3$
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ABSTRACT: We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi one-dimensional spin 1/2 antiferromagnet KCuF$_3$. Signals from two distinct sites are resolved which have a temperature dependent frequency shift which is different than the magnetic susceptibility. This difference is attributed to a muon induced perturbation of the spin 1/2 chain. Comment: 13 pages, 4 figures, The 2002 International Conference on Muon Spin Rotation, Relaxation and Resonance, Virginia. USA10/2002; -
Article: Anomalous weak magnetism in superconducting YBa2Cu3O6+x
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ABSTRACT: For some time now, there has been considerable experimental and theoretical effort to understand the role of the normal-state "pseudogap" phase in underdoped high-temperature cuprate superconductors. Recent debate has centered on the question of whether the pseudogap is independent of superconductivity. We provide evidence from zero-field muon spin relaxation measurements in YBa2Cu3O6+x for the presence of small spontaneous static magnetic fields of electronic origin intimately related to the pseudogap transition. Our most significant finding is that, for optimal doping, these weak static magnetic fields appear well below the superconducting transition temperature. The two compositions measured suggest the existence of a quantum critical point somewhat above optimal doping. -
Article: Correlations between charge ordering and local magnetic fields in overdoped YBa2Cu3O6+x
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ABSTRACT: Zero-field muon spin-relaxation (ZF-?SR) measurements were undertaken on under- and overdoped samples of superconducting YBa2Cu3O6+x to determine the origin of the weak static magnetism recently reported in this system. The temperature dependence of the muon spin-relaxation rate in overdoped crystals displays an unusual behavior in the superconducting state. A comparison to the results of NQR and lattice structure experiments on highly doped samples provides compelling evidence for strong coupling of charge, spin, and structural inhomogeneities. -
Article: Zero-field [mu]SR study of YBa2Cu3O6+x, x[greater-or-equal, slanted]0.67: evidence for charge ordering
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ABSTRACT: Zero-field (ZF) [mu]SR measurements were performed on single crystals of the high temperature superconductor YBa2Cu3O6+x, for x[greater-or-equal, slanted]0.67. Contrary to early ZF-[mu]SR studies, we find that the muon-spin relaxation function evolves significantly as a function of temperature and oxygen content. The relaxation rate of the ZF-[mu]SR time spectra exhibits a local minimum near 55?K and a subsequent increase with decreasing temperature. These features weaken considerably with decreasing x. A comparison to the results of nuclear quadrupole resonance experiments on highly doped samples suggests that these observations are associated with the build up of long-range charge correlations and not spontaneous orbital moments as suggested by Sonier et al. (Science 292 (2001) 1692). -
Article: Early 8Li+[beta]-NMR investigations in GaAs and Ge
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ABSTRACT: In this paper, we describe initial studies of the structure and dynamics associated with in bulk crystalline GaAs and Ge. At low temperatures in GaAs, the amplitude of the resonance signal at indicates that a large fraction (at least 70%) of the Li end up in locations with cubic symmetry (i.e. the tetrahedral interstitial and substitutional sites). The linewidth of the [beta]-NMR resonance increases dramatically above 150?K, reaches a maximum at about 290?K, and decreases again. This suggests that the Li starts to change its location, probably from an interstitial to a substitutional site, at . Experiments in Ge are also described. In this sample, a narrow resonance is seen at low temperatures that is likely due to Li located at an interstitial site. Near room temperature, it appears that Li is converting to another site.
