M. Buchholz

Publications (4)14.77 Total impact

• Article: Charge stripe order near the surface of 12-percent doped La₂-xSrxCuO₄.

  H-H Wu, M Buchholz, C Trabant, C F Chang, A C Komarek, F Heigl, M V Zimmermann, M Cwik, F Nakamura, M Braden, C Schüßler-Langeheine
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  ABSTRACT: A collective order of spin and charge degrees of freedom into stripes has been predicted to be a possible ground state of hole-doped CuO(2) planes, which are the building blocks of high-temperature superconductors. In fact, stripe-like spin and charge order has been observed in various layered cuprate systems. For the prototypical high-temperature superconductor La(2-x)Sr(x)CuO(4), no charge-stripe signal has been found so far, but several indications for a proximity to their formation. Here we report the observation of a pronounced charge-stripe signal in the near surface region of 12-percent doped La(2-x)Sr(x)CuO(4). We conclude that this compound is sufficiently close to charge stripe formation that small perturbations or reduced dimensionality near the surface can stabilize this order. Our finding of different phases in the bulk and near the surface of La(2-x)Sr(x)CuO(4) should be relevant for the interpretation of data from surface-sensitive probes, which are widely used for La(2-x)Sr(x)CuO(4) and similar systems.
  Nature Communications 08/2012; 3:1023. · 7.40 Impact Factor
• Article: Symmetry of Orbital Order in Fe3O4 Studied by Fe L 2;3 Resonant X-Ray Diffraction

  A Tanaka, C F Chang, M Buchholz, C Trabant, E Schierle, J Schlappa, D Schmitz, H Ott, P Metcalf, L H Tjeng, C Schüßler-Langeheine
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  ABSTRACT: We studied the symmetry of the Fe 3d wave function in magnetite below the Verwey temperature T V with resonant soft-x-ray diffraction. Although the lattice structure of the low-temperature phase of Fe 3 O 4 is well described by the pseudo-orthorhombic Pmca with a slight monoclinic P2=c distortion, we find that the 3d wave function does not reflect the Pmca symmetry, and its distortion toward monoclinic symmetry is by far larger than that of the lattice. The result supports a scenario in which the Verwey transition involves the ordering of t 2g orbitals with complex-number coefficients.
  Physical Review Letters 01/2012; · 7.37 Impact Factor
• Source

  Available from: ArXiv

  Article: Intrinsic and extrinsic x-ray absorption effects in soft x-ray diffraction from the superstructure in magnetite

  C F Chang, J. Schlappa, M. Buchholz, A Tanaka, E. Schierle, D. Schmitz, H. Ott, R. Sutarto, T. Willers, P. Metcalf, L. H. Tjeng, C. Schuessler-Langeheine
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  ABSTRACT: We studied the (001/2) diffraction peak in the low-temperature phase of magnetite (Fe3O4) using resonant soft x-ray diffraction (RSXD) at the Fe-L2,3 and O-K resonance. We studied both molecular-beam-epitaxy (MBE) grown thin films and in-situ cleaved single crystals. From the comparison we have been able to determine quantitatively the contribution of intrinsic absorption effects, thereby arriving at a consistent result for the (001/2) diffraction peak spectrum. Our data also allow for the identification of extrinsic effects, e.g. for a detailed modeling of the spectra in case a "dead" surface layer is present that is only absorbing photons but does not contribute to the scattering signal.
  01/2011;
• Source

  Available from: ArXiv

  Article: Atomic multiplet calculation of 3d_{5/2} -> 4f resonant x-ray diffraction from Ho metal

  M. W. Haverkort, C. Schüßler-Langeheine, C F Chang, M. Buchholz, H. -H. Wu, H. Ott, E. Schierle, D. Schmitz, A Tanaka, L. H. Tjeng
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  ABSTRACT: We compare for Ho metal the x-ray absorption spectrum and the resonant soft x-ray diffraction spectra obtained at the $3d_{5/2} \to 4f$ ($M_5$) resonance for the magnetic 1st and 2nd order diffraction peaks $(0,0,\tau)$ and $(0,0,2\tau)$ with the result of an atomic multiplet calculation. We find a good agreement between experiment and simulation giving evidence that this kind of simulation is well suited to quantitatively analyze resonant soft x-ray diffraction data from correlated electron systems.
  06/2008;