Hidden Magnetic Texture in the Pseudogap Phase of High-Tc $YB{a}_{2}C{u}_3{O}_{6.6}$

Abstract

Despite decades of intense researches, the enigmatic pseudo-gap (PG) phase of superconducting cuprates remains an unsolved mystery. In the last 15 years, various symmetry breakings in the PG state have been discovered, spanning an intra-unit cell (IUC) magnetism, preserving the lattice translational (LT) symmetry but breaking time-reversal symmetry and parity, and an additional incipient charge density wave breaking the LT symmetry upon cooling. However, none of these states can (alone) account for the partial gapping of the Fermi surface. Here we report a hidden LT-breaking magnetism uisng polarized neutron diffraction. Our measurements reveal magnetic correlations, in two different underdoped $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6.6}$ single crystals, that settle at the PG onset temperature with i) a planar propagation wave vector $(\pi ,0)\equiv (0,\pi )$, yielding a doubling or quadrupling of the magnetic unit cell and ii) magnetic moments mainly pointing perpendicular to the $Cu{O}_2$ layers. The LT-breaking magnetism is at short range suggesting the formation of clusters of 5-6 unit cells. Together with the previously reported IUC magnetism, it yields a hidden magnetic texture of the $Cu{O}_2$ unit cells hosting loop currents, forming large supercells which may be crucial for elucidating the PG puzzle.

5 figures, supplementary file upon request

References in corpus (8)

• Magnetic order in the pseudogap phase of high-$T_C$ superconductors
• Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy
• Thermodynamic evidence for nematic phase transition at the onset of pseudogap in YBa${}_2$Cu${}_3$O${}_y$
• Emergent loop current order from pair density wave superconductivity
• Evidence for competing magnetic instabilities in underdoped $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6+\mathrm{x}}$
• a-b anisotropy of the intra-unit-cell magnetic order in $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6.6}$
• Loop currents in quantum matter
• Pseudogap and Fermi-arcs in underdoped cuprates

Cited by in corpus (7)

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• Search for orbital magnetism in the kagome superconductor $\mathrm{Cs}{\mathrm{V}}_3\mathrm{S}{\mathrm{b}}_5$ using neutron diffraction
• Universality of the {\bf q}=1/2 Orbital Magnetism in the Pseudogap Phase of the High-$T_c$ superconductor $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6+\mathrm{x}}$
• Interplay between the charge density wave phase and a pseudogap under antiferromagnetic correlations
• Orbital current signature using neutron diffraction