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A study of the high-field Hall coefficient in thallium- and bismuth-based single-layer cuprates demonstrates a smooth evolution of this quantity from p to 1 + p over a wide doping range.

Incoherent transport is an important feature of many anisotropic quantum materials but often its origin is not well understood. Here, the authors show that in a layered quantum magnet, incoherence is driven by the interaction of electrons with spin fluctuations after the melting of magnetic 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.

Recent advancements in the sample quality of infinite-layer nickelates have made systematic comparisons with cuprates increasingly relevant. Hsu et al. report anomalous electronic transport in high-crystallinity (Nd,Sr)NiO₂ at large magnetic fields, map out the transport phase diagram, and discuss similarities and differences with cuprates.

The pseudogap in cuprates is often linked to superconductivity. Now bulk evidence for a pseudogap is found in doped non-superconducting Sr₂IrO₄, revealing that pseudogaps in doped Mott insulators are not necessarily a precursor to superconductivity.

Understanding “strange metal" behavior in high-temperature superconductors remains an open problem. Here the authors report a correlation between linear-in-magnetic-field magnetoresistance and linear-in-temperature resistivity in several hole-doped cuprate families and discuss its possible implications for superconductivity.

The underlying physics of the strange metal phase observed in many strongly correlated materials is not well understood. Now, evidence emerges that antiferromagnetic spin fluctuations play an important role.

South Africa experienced a resurgence in COVID-19 in 2022 driven by Omicron subvariants BA.4 and BA.5. Here, the authors investigate the severity of infections caused by these subvariants, and find no difference in the risk of severe outcomes when compared to Omicron BA.1, whilst all Omicron subvariants were less severe than Delta.

In a quantum vortex liquid, the superconducting vortex lattice is melted by quantum fluctuations instead of thermal fluctuations. Here, the authors present high-field magnetotransport measurements of FeSe_1−xS_x and FeSe_1−xTe_x, which provide evidence for a broad quantum vortex liquid regime.

Interacting electrons in one dimension are predicted to have independent spin and charge excitations. Wakehamet al. show evidence of this behaviour in a bulk conductor by measuring a ratio of thermal to electrical conductivity orders of magnitude larger than in conventional three-dimensional metals.

A significant enhancement in the effective mass of Dirac-like quasiparticles residing near a nodal loop in the electronic band structure provides evidence for strong correlation effects in a topological semimetal.

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.

Strange metal behaviour of high-Tc superconductors, characterised by unconventional electrical and thermodynamic properties, still poses challenges for theory. Smit et al. report experimental features in the self-energy of a strange metal that are consistent with predictions by holographic theoretical methods.

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.

In Weyl semimetals, unusual electronic transport phenomena are predicted to occur, such as an axial anomaly which violates the conservation of chiral fermions. Here, the authors evidence such behaviour via the occurrence of negative magnetoresistance in layered high-purity non-magnetic metals.

Quantum critical behaviour has been observed in many metallic systems that do not behave conventionally as Fermi liquids. High-magnetic-field experiments now reveal clear evidence for quantum criticality in an iron-based high-temperature superconductor.

Loss-of-function mutations in tumour suppressor genes are associated with oesophageal adenocarcinoma (EAC), but the mechanisms underlying EAC development remain unclear. Here, the authors show that EACs present a high frequency of genomic catastrophes resulting in amplification of potent oncogenes.

Measurements of high-field magnetotransport in overdoped cuprates indicate that the strange-metal regime exists beyond the critical doping, and that it has both coherent and incoherent contributions.

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.

The authors use resonant X-ray scattering to study the cuprate superconductor YBa₂Cu₄O₈, which has low disorder due to its stoichiometric nature. They report a diffraction signature of incommensurate, quasi-2D charge order that onsets below T* = 200 K, coincident with the pseudogap.

Carbon isotopic analysis reveals global biogeographic traits in shark trophic interactions, and sheds light on the diverse foraging behaviour of sharks.

Disentangling the physics of the pseudogap phase from the other electronic phases of high-temperature superconductors has long been a frustrating problem. A recent high-field experiment has isolated it completely — thus raising hopes that its origin can finally be understood.

CD4⁺ T helper cells producing IL-17A (T_H17 cells) can take on pathogenic or anti-inflammatory functions in context-specific manners. Here the authors show that the anti-inflammatory fate of T_H17 cells contributes, via TGF-β signaling and induction of IL-10, to host immune tolerance, but also simultaneously dampens protective immunity against S. aureus.

Superconducting phase fluctuations are often associated with the pseudogap phase of the copper-oxide superconductors. However, the same fluctuations exist in the overdoped part of the phase diagram where the pseudogap is absent, suggesting that phase fluctuations are independent of the pseudogap

BCG vaccine confers only partial protection against tuberculosis. Here the authors show that the risk of tuberculosis infection and progression to disease in BCG-immunized children positively correlates with the frequency of activated HLA-DR⁺CD4⁺T cells.

Lymphocyte function is regulated by phosphatidylinositol-dependent pathways. Uzel and colleagues identify a cohort of immunodeficient patients with hyperactive phosphatidylinositol-3-OH kinase activity due to mutant p110δ subunits, which results in enhanced senescence of cells of the immune system.

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.

Analysis of peripheral mycobacteria-reactive CD4⁺ T cell receptor sequences from individuals infected with Mycobacterium tuberculosis shows a high degree of overlap between progressors and controllers, but points to some distinct clonotypes that are enriched in either group.