Local magnetic order in La2CuO4 seen via μ+SR spectroscopy

[摘要] The origin of a pseudogap in the underdoped phase of cuprates has become one of the leading issues in understanding the mechanism(s) of high-Tc superconductivity. Several experiments (i.e. polarized neutron diffraction studies) support theoretical models based on the circulating current (CC) picture. These CC models suggest a novel ordered phase formed by orbital magnetic moments caused by spontaneous orbital currents. However to date, μSR experiments in cuprate superconductors have not revealed any magnetic field higher than 0.2 G associated with orbital moments. Here we present high magnetic field μSR spectroscopy of a stoichiometric La2CuO4 crystal which shows antiferromagnetic splittings and additional 45 G line splittings, consistent with orbital currents.

[发布机构] Kurchatov Institute, Kurchatov Sq. 1, Moscow; 123182, Russia^1;Department of Physics and Astronomy, University of British Columbia, Vancouver; BC; V6T 1Z1, Canada^2;Bruker BioSpin AG, Industriestrasse 26, Fallanden; 8117, Switzerland^3;Department of Physics, Texas Tech University, Lubbock; TX; 79409-1051, United States^4;Institute of Solid State and Semiconductor Physics, National Academy of Sciences of Belarus, Minsk; 220072, Belarus^5

[关键词] Antiferromagnetics;Circulating current;High magnetic fields;High-Tc superconductivity;Line splittings;Magnetic orders;Orbital magnetic moment;Polarized neutron diffraction