Graeme M. Luke

Learn More
In addition to its importance for existing and potential applications, superconductivity[1] is one of the most interesting phenomena in condensed matter physics. Although most superconducting materials are well-described in the context of the Bardeen Cooper and Schrieffer (BCS) theory[2], considerable effort has been devoted to the search for exotic systems(More)
V 2 O 3 nanocrystals can be synthesized through hydrothermal reduction in VO͑OH͒ 2 using hydrazine as a reducing agent. Addition of different ligands to the reaction produces nanoparticles, nanorods, and nanoplate-lets of different sizes. Small nanoparticles synthesized in this manner show suppression of the magnetic phase transition to lower temperatures.(More)
We report elastic neutron diffraction and muon spin relaxation (µSR) measurements of the quasi one-dimensional antiferromagnets Sr 2 CuO 3 and Ca 2 CuO 3 , which have extraordinarily reduced T N /J ratios. We observe almost resolution-limited antiferromagnetic Bragg reflections in Sr 2 CuO 3 and obtain a reduced ordered moment size of ∼0.06µ B. We find that(More)
We present high-resolution angle-resolved photoemission spectra of the heavy-fermion superconductor URu2Si2. Detailed measurements as a function of both photon energy and temperature allow us to disentangle a variety of spectral features, revealing the evolution of the low-energy electronic structure across the "hidden order" transition. Above the(More)
Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and(More)
RENiO3 (RE=rare-earth element) and V2O3 are archetypal Mott insulator systems. When tuned by chemical substitution (RENiO3) or pressure (V2O3), they exhibit a quantum phase transition (QPT) between an antiferromagnetic Mott insulating state and a paramagnetic metallic state. Because novel physics often appears near a Mott QPT, the details of this(More)
A "supercooled" liquid develops when a fluid does not crystallize upon cooling below its ordering temperature. Instead, the microscopic relaxation times diverge so rapidly that, upon further cooling, equilibration eventually becomes impossible and glass formation occurs. Classic supercooled liquids exhibit specific identifiers including microscopic(More)
Within a Kondo lattice, the strong hybridization between electrons localized in real space (r-space) and those delocalized in momentum-space (k-space) generates exotic electronic states called 'heavy fermions'. In URu(2)Si(2) these effects begin at temperatures around 55 K but they are suddenly altered by an unidentified electronic phase transition at T(o)(More)
  • 1