Novel magnetic order in the pseudogap state of high-Tccopper oxides superconductors

Abstract

One of the leading issues in high-Tc copper oxide superconductors is the origin of the pseudogap phase in the underdoped regime of their phase diagram. Using polarized neutron diffraction, a novel magnetic order has been identified as an hidden order parameter of the pseudogap as the transition temperature corresponds to what is expected for the pseudogap. The observed magnetic order preserves translational symmetry as predicted for orbital moments in the circulating current theory. Being now reported in three different cuprates familles, it appears as a universal phenomenon whatever the crystal structure (with single CuO2 layer or bilayer per unit cell). To date, it is the first direct evidence of an hidden order parameter characterizing the pseudogap phase of high-Tc cuprates.To cite this article: P. Bourges and Y. Sidis, C. R. Physique xx (2010). RésuméOrdre magnétique de l'état pseudogap des oxydes de cuivre supraconducteursà haute température critique Un des problèmes majeurs des oxydes de cuivre supraconducteursà haute température critique est l'origine de la phase pseudogap dans l'état sous-dopé. En utilisant des mesures de diffraction de neutrons polarisés, nous avons identifié un ordre magnétique caché qui apparaîtà la température attendue de cetétat de pseudogap. Cet ordre magnétique respecte la symétrie de translation du réseau comme cela aété prédit dans la théorie des boucles de courants circulants. Nous avons généralisé cette découverte dans trois familles distinctes de cuprates. Cette mesure est la première preuve expérimentale directe d'un paramètre d'ordre universel de l'état de pseudogap des oxydes de cuivre supraconducteurs. Pour citer cet article : P. Bourges et Y. Sidis, C. R. Physique xx (2010).

Universal disorder in Bi2Sr2CaCu2OAlldredge1, Fujita2, Eisaki3 et al. 2013Phys. Rev. B

“…This shows there is no variation of the length scale for any of the three energy scales. A recent neutron scattering study 37 has detected a q = 0 (or Q x,y ) spin structure in the pseudogap state that could correspond to the excitations observed at E =  1 by SI-STM 4,8,9 . There are also other proposed smectic spin stripes that could correspond to the pseudogaps S x,y 38 .…”

Berry phase and anomalous Hall effect in a three-orbital tight-binding Hamiltonian

“…Orbital current loops without changing translational symmetry were predicted to arise as broken symmetry states due to interactions in a three-orbital per unit cell model for underdoped cuprates [7][8][9] and have been discovered in several families of cuprates [10][11][12]. These loop-current states, however, do not lead to the quantized anomalous Hall effect (QAHE) or "Chern insulator" discussed by Haldane.…”

Absence of Static Loop-Current Magnetism at the Apical Oxygen Site inHgBa2CuO4+δfrom NMR

“…The NMR frequency shifts are consistent with a dipolar field from the Cu +2 site. [14] show the appearance of broken time reversal symmetry that correlates with the onset of the pseudogap phase with a magnetic moment tilted away from the crystalline c-axis. A muon spin relaxation (µSR) experiment in zero field was unable to detect this magnetism [15] although screening effects may account for muon insensitivity.…”