Dr Clemens Ulrich
Staff Profile
Role at ANSTO
Clemens Ulrich started his scientific research with Raman Light Scattering in semiconductors under high hydrostatic pressure in 1994 at the Max-Planck institute for solid state research in Stuttgart, where he performed his PhD thesis in the group of M. Cardona.
The main topics of his research in the last 10 years were strongly correlated electron systems like unconventional superconductors or transition metal oxides. Of special interest were the effects of spin, charge, and orbital correlations in 3-dimensional perovskite systems with partly occupied 3d-electronic levels. The used experimental techniques were inelastic neutron scattering, Raman lights scattering, and resonant inelastic x-ray scattering (ESRF/Grenoble and PSI/Switzerland).
The combination of these complementary techniques allowed to yield a detailed insight in the physics behind strongly correlated electron systems.
Clemens was the group leader of the Raman laboratories at the Max-Planck Institute in Stuttgart. He was involved in inelastic neutron scattering experiments (triple-axis-spectrometers and time-of-flight spectrometers). In order to determine the crystallographic and magnetic structure Clemens has also carried out neutron and synchrotron x-ray diffraction experiments in close collaboration with Dr. M. Reehuis at the Hahn-Meitner Institute in Berlin and Dr. P. Pattison at the ESRF in Grenoble.
Clemens has more than 55 refereed publications in high-impact journals in magnetism, strongly correlated electron materials and condensed matter physics. His Hirsch index is 17.
Clemens joined ANSTO in April 2009 in a joint position with the University of New South Wales in Sydney. He will perform neutron scattering experiments at the OPAL research reactor at ANSTO and Raman light scattering experiments at the UNSW in Sydney.
Publications
M. Reehuis, C. Ulrich, K. Prokes, S. Matas,1 J. Fujioka, S. Miyasaka, Y. Tokura, and B. Keimer, Structural and magnetic phase transitions of the orthovanadates RVO3 (R = Dy, Ho, Er) as seen via neutron diffraction, Phys. Rev. B 83, 064404 (2011)
M. Rahlenbeck, M. Wagenknecht, A. Tsukada, D. Koelle, R. Kleiner, B. Keimer, and C. Ulrich, Raman light scattering study and microstructural analysis of epitaxial films of the electron-doped superconductor La2-xCexCuO4, European Physical Journal B 75, 461 (2010).
C. Ulrich, L.J.P. Ament, G. Ghiringhelli, L. Braicovich, M. Moretti Sala, N. Pezzotta, T. Schmitt, G. Khaliullin, J. van den Brink, H. Roth, T. Lorenz, and B. Keimer, Momentum Dependence of Orbital Excitations in Mott-Insulating Titanates, Phys. Rev. Lett. 103, 107205 (2009)
M. Bakr, A. P. Schnyder, L. Klam, D. Manske, C. T. Lin, B. Keimer, M. Cardona, and C. Ulrich, Electronic and phononic Raman scattering in detwinned YBa2Cu3O6.95 and Y0.85Ca0.15Ba2Cu3O6.95: s-wave admixture to the dx2-y2-wave order parameter, Phys. Rev. B 80, 064505 (2009)
M. Rahlenbeck, G.L. Sun, D.L. Sun, C.T. Lin, B. Keimer, and C. Ulrich, Phonon anomalies in pure and underdoped R1-xKxFe2As2 (R=Ba, Sr) investigated by Raman light scattering, Phys. Rev. B 80, 064509 (2009)
M. Rahlenbeck, G. L. Sun, D. L. Sun, C. T. Lin, B. Keimer, and C. Ulrich, Phonon anomalies in pure and underdoped R[sub 1 - x]K[sub x]Fe[sub 2]As[sub 2] (R = Ba, Sr) investigated by Raman light scattering, Phys. Rev. B, 80(6), Art. No. 064509 (2009).
C. Ulrich, G. Ghiringhelli, A. Piazzagalli, L. Braicovich, N.B. Brookes, H. Roth, T. Lorenz and B. Keimer Orbital excitations in YTiO3 and LaTiO3 probed by resonant inelastic x-ray scattering Phys. Rev. B 77, 113102 (2008)
C. Ulrich, A. G ssling, M. Gr ninger, M. Guennou, H. Roth, M. Cwik, T. Lorenz, G. Khaliullin and B. Keimer Raman Scattering in the Mott Insulators LaTiO3 and YTiO3: Evidence for Orbital Excitations Phys. Rev. Lett. 97, 157401 (2006)
S. Pailhes, C. Ulrich, B. Fauque, V. Hinkov, Y. Sidis, A. Ivanov, C.T. Lin, B. Keimer and P. Bourges Doping Dependence of Bilayer Resonant Spin Excitations in (Y,Ca)Ba2Cu3O6+x Phys. Rev. Lett. 96, 257001 (2006)
C. Ulrich, G. Khaliullin, J. Sirker, M. Reehuis, M. Ohl, S. Miyasaka, Y. Tokura and B. Keimer Magnetic neutron scattering study of YVO3: Evidence for an orbital Peierls state Phys. Rev. Lett. 91, 257202 (2003)
C. Ulrich, G. Khaliullin, S. Okamoto, M. Reehuis, A. Ivanov, H. He, Y. Taguchi, Y. Tokura and B. Keimer Magnetic order and dynamics in an orbitally degenerate ferromagnetic insulator Phys. Rev. Lett. 89, 167202 (2002)
H. He, P. Bourges, Y. Sidis, C. Ulrich, L.P. Regnault, S. Pailhes, N.S. Berzigiarova, N.N. Kolesnikov and B. Keimer Magnetic resonant mode in the single-layer high-temperature superconductor Tl2Ba2CuO6+d Science 295, 1045 (2002)
Y. Sidis, C. Ulrich, P. Bourges, C. Bernhard, C. Niedermayer, L.P. Regnault, N.H. Andersen and B. Keimer Antiferromagnetic ordering in superconducting YBa2Cu3O6.5 Phys. Rev. Lett. 86, 4100 (2001)
J.W. Lynn, B. Keimer, C. Ulrich, C. Bernhard and J.L. Tallon Antiferromagnetic ordering of Ru and Gd in superconducting RuSr2GdCu2O8 Phys. Rev. B 61, R14964 (2000)
C. Ulrich, A. G bel, K. Syassen, and M. Cardona, Pressure-induced disappearance of the Raman anomaly in CuCl Phys. Rev. Lett. 82, 351 (1999)
C. Ulrich, E. Anastassakis, K. Syassen, A. Debernardi and M. Cardona Lifetime of phonons in semiconductors under pressure Phys. Rev. Lett. 78, 1283 (1997)