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This paper reports the observation of quantum oscillations in the overdoped superconductor Tl₂Ba₂CuO_6+δ that show the existence of a large Fermi surface of well-defined quasiparticles covering two-thirds of the Brillouin zone. These measurements firmly establish the applicability of a generalized Fermi-liquid picture on the overdoped side of the superconducting dome.

The interplay between superconductivity and competing orders in multi-layered cuprates can shed light on the nature of the superconducting pairing. Here, the authors report on the coexistence of antiferromagnetic and charge orders in different CuO2 planes in a tri-layer cuprate, pointing to a magnetically-mediated mechanism.

A genetic-algorithm approach to analysing quantum oscillations in a high-temperature superconductor reveals that quasiparticles behave as nearly free spins—split into spin-up and spin-down populations, known as the Zeeman effect.

Achieving high conductivity in metal-organic solids can be challenging, due to the difficulty of obtaining a good overlap between the d-orbitals of the metal and the π-orbitals of the organic molecule. Here, the authors present two coordination solids, VCl₂(pyrazine)₂ and TiCl₂(pyrazine)₂, with remarkably different electrical conductivity. While the former is an insulator, the latter displays the highest conductivity of any octahedrally coordinated metal ions based metal-organic solid.

The recent discovery of charge order in YBa₂Cu₃O_y was unexpected. A systematic study of the evolution of this phenomenon as a function of magnetic field conducted by Wu et al. reveals how the competition between charge order and superconductivity may actually be universal to the underdoped cuprates.

Fully mapping the Fermi surface of a compound provides a clear picture of its fundamental properties. Through thermoelectric measurements of the underdoped cuprate YBa₂Cu₃O_y, this study shows evidence for a second Fermi pocket, consistent with charge–density–wave Fermi surface reconstruction.

Every metal has an underlying Fermi surface that gives rise to quantum oscillations. So far, quantum oscillation measurements in the superconductor YBCO have been inconclusive owing to the structural complexities of the material. Quantum oscillations in a Hg-based cuprate—with a much simpler structure—help to establish the origin and universality of the oscillations.

The point at which a magnetic field kills superconductivity in the cuprates has been difficult to measure. Grissonnanche et al. use thermal conductivity measurements to reliably determine this field and find that it drops suddenly below some critical doping, suggesting the onset of a new competing phase.

Charge–density–wave correlations, quantum oscillations and Fermi-liquid charge transport are at the centre of a heated debate in cuprate superconductivity. Using resonant X-ray scattering, Tabis et al. investigate the charge order and its link to the electronic transport properties in HgBa₂CuO_4+δ.

A transport study of overdoped cuprates reveals a resistivity that is linear as the temperature approaches 0 K, and is associated with a universal scattering rate.

The observation of a negative Hall resistance in the magnetic-field-induced normal state of underdoped 'YBCO'materials, which reveals that these pockets are electron-like rather than hole-like. It is proposed that these electron pockets most probably arise from a reconstruction of the Fermi surface caused by the onset of a density-wave phase, as is thought to occur in the electron-doped copper oxides near the onset of antiferromagnetic order.

Low-temperature measurements of the Hall effect in cuprate materials in which superconductivity is suppressed by high magnetic fields show that the pseudogap is not related to the charge ordering that has been seen at intermediate doping levels, but is instead linked to the antiferromagnetic Mott insulator at low doping.

A thermodynamic probe of the recently discovered charge-density-wave order in YBa₂Cu₃O_y reveals a biaxial modulation in magnetic fields up to 40 T.