Loop currents in quantum matter

Abstract

In many quantum materials, strong electron correlations lead to the emergence of new states of matter. In particular, the study in the last decades of the complex phase diagram of high temperature superconducting cuprates highlighted intra-unit-cell electronic instabilities breaking discrete Ising-like symmetries, while preserving the lattice translation invariance. Polarized neutron diffraction experiments have provided compelling evidences supporting a new form of intra-unit-cell magnetism, emerging concomitantly with the so-called pseudogap state of these materials. This observation is currently interpreted as the magnetic hallmark of an intra-unit-cell loop current order, breaking both parity and time-reversal symmetries. More generally, this magneto-electric state is likely to exist in a wider class of quantum materials beyond superconducting cuprates. For instance, it has been already observed in hole-doped Mott insulating iridates or in the spin liquid state of hole-doped 2-leg ladder cuprates.

7 figures, 1 glossary, accepted in Comptes Rendus Physique (2021)

References in corpus (24)

• Theory of Intertwined Orders in High Temperature Superconductors
• Magnetic order in the pseudogap phase of high-$T_C$ superconductors
• Polar Kerr Effect Measurements of YBa2Cu3O6+x: Evidence for Broken Symmetry Near the Pseudogap Temperature
• Phase competition in trisected superconducting dome
• Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy
• Direct phase-sensitive identification of a d-form factor density wave in underdoped cuprates
• Thermodynamic evidence for nematic phase transition at the onset of pseudogap in YBa${}_2$Cu${}_3$O${}_y$
• Orbital currents in extended Hubbard models of high-T${}_c$ cuprates
• Intertwined order and holography: the case of the parity breaking pair density wave
• 2D orbital-like magnetic order in $\mathrm{L}{\mathrm{a}}_{2-\mathrm{x}}\mathrm{S}{\mathrm{r}}_{\mathrm{x}}\mathrm{Cu}{\mathrm{O}}_4$
• Strange metals as ersatz Fermi liquids
• Emergent loop current order from pair density wave superconductivity
• Evidence for competing magnetic instabilities in underdoped $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6+\mathrm{x}}$
• No Evidence for Orbital Loop Currents in Charge Ordered YBa${}_2$Cu${}_3$O${}_{6+x}$ from Polarized Neutron Diffraction
• a-b anisotropy of the intra-unit-cell magnetic order in $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{6.6}$
• Anomalous mirror symmetry breaking in a model insulating cuprate Sr${}_2$CuO${}_2$Cl${}_2$
• Thermodynamic Properties near the onset of Loop-Current Order in high-$T_c$ superconducting cuprates
• Pseudogap and Fermi-arcs in underdoped cuprates
• Emergence of Charge Loop Current in Geometrically Frustrated Hubbard Model: Functional Renormalization Group Study
• Specific Heat and Sound Velocity Distinguish the Relevant Competing Phase in the Pseudogap Region of High Temperature Superconductors
• Muon Spin Relaxation and fluctuating magnetism in the pseudogap phase of YBa${}_2$Cu${}_3$O${}_y$
• Ferro-type order of magneto-electric quadrupoles as an order-parameter for the pseudo-gap phase of a cuprate superconductor
• Loop currents in ladder cuprates: A dynamical mean field theory study
• Pseudogap in Cuprates by Electronic Raman Scattering

Cited by in corpus (7)

• Probing octupolar hidden order via Janus impurities
• Neutron scattering from local magnetoelectric multipoles: a combined theoretical, computational, and experimental perspective
• Hidden Magnetic Texture in the Pseudogap Phase of High-Tc $YB{a}_{2}C{u}_3{O}_{6.6}$
• Evidence for Quantum Stripe Ordering in a Triangular Optical Lattice
• Local magnetic moments due to loop currents in metals
• Bragg diffraction by a magnetic all-in-all-out configuration with application to a cubic cerium pyrochlore oxide
• Quantum-critical transport in marginal Fermi liquids