Speaker
Dr
V Scagnoli
(Swiss Light Source, Paul Scherrer Institut, CH 5232 Villigen PSI, Switzerland)
Description
Cupric oxide (CuO) has recently attracted much interest as a magnetically driven multiferroic with the highest Tc (~230K). In this material a non-collinear spiral magnetic order (215K<T<230K) breaks crystal inversion symmetry, inducing ferroelectricity. We use resonant x-ray diffraction at the Cu L edges to probe the subtle changes in the Cu electronic structure occurring at the appearance of multiferroicity and test the magnetic ground-state, proposed by neutron diffraction, to be a collinear antiferromagnet. In both phases we have found a strong dependence of the diffracted intensity on the polarization of the incident light. Such dependence is totally unexpected in a simple collinear antiferromagnetic phase. In this model the Cu magnetic moment are aligned (antiferromagnetically) along the b-axis. The observed polarization dependence could reflect and be a direct measurement of the presence of orbital currents surrounding the Cu ions. Such observations are long sought proofs for theoretical model explaining the behavior of the normal state of high-Tc superconductors. Understanding such state is the key to unravel the true origin of the superconducting phase transition in cuprates materials.
Please specify the session
RIXS
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Talk
Primary author
Dr
V Scagnoli
(Swiss Light Source, Paul Scherrer Institut, CH 5232 Villigen PSI, Switzerland)
Co-authors
Prof.
A T Boothroyd
(Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK)
Dr
D Prabhakaran
(Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK)
Dr
M Garganourakis
(Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland)
Dr
R de Souza
(Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland)
Prof.
S W Lovesey
(ISIS Facility, RAL, Oxfordshire OX11 0QX, UK)
Dr
U Staub
(Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland)
Dr
Y Bodenthin
(Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland)
