Search

The spin-orbit interaction is central to the defining characteristics of topological insulators. Here, Jozwiaket al. report a spin-polarized unoccupied surface resonance coevolving with topological surface states from a pair of Rashba-like states through spin-orbit induced band inversion.

Twisted bilayer (tb) MoTe₂ is an ideal platform for investigating the fractional quantum anomalous Hall effect but issues related to air sensitivity make the study of its electronic structure experimentally challenging. As a solution, the authors prepare hBN encapsulated tb-MoTe₂ and using micro-angle resolved photoemission spectroscopy determine the band structure. Furthermore, through in-situ alkali metal deposition, they obtain evidence indicating a direct band gap.

Superconductivity is the result of many-body interactions between excitations in a solid. Zhang et al.use time- and angle-resolved photoemission to compare photo-induced changes in the electron self-energy of a unconventional superconductor to those in a related material in the metallic state.

The authors find low-energy magnetic excitations and a flat band near the Fermi level in kagome metal superconductor CsCr3Sb5 by angle-resolved photoemission and resonant inelastic X-ray scattering. They suggest that the flat band plays a role in the emergence of charge/magnetic order at low temperatures.

Tomonaga-Luttinger liquid behavior has been observed within 1D defects in transition metal dichalcogenides. Here, using complementary experiments and engineered defects, the authors demonstrate the importance of graphene as a substrate and its role in the formation of this quasiparticle excitation in 2D WS₂.

Synthesis of heterostructures of magnetic intercalation compounds in transition metal dichalcogenides (TMDs) via directed topotactic reactions enables the creation of multi-component magnetic architectures, overcoming limitations of crystallographic incommensurability

The advantage of living in cities compared with rural areas with respect to height and BMI in children and adolescents has generally become smaller globally from 1990 to 2020, except in sub-Saharan Africa.

Chromium sulfur bromide is an air-stable van der Waals magnet, which has a large optical response. Here, Smolenski et al find a large exciton binding energy CrSBr, which they attribute to localization due to the quasi one-dimensional electronic bands.

Experiments that directly probe the quantum geometric tensor in solids have not been reported. Now, the quantum metric and spin Berry curvature—dual components of the quantum geometric tensor—have been simultaneously measured in reciprocal space.

Angle-resolved photoemission spectroscopy of superconducting magic-angle twisted bilayer graphene reveals flat-band replicas that are indicative of strong electron–phonon coupling; these replicas are absent in non-superconducting twisted bilayer graphene.

The authors develop a high-spatial-resolution photoemission technique to show variation of the energy of the Dirac point of approximately 50 meV. They also find an interplay between bulk and surface states.

The flat electronic bands that are associated with ordered phases in twisted bilayer graphene at a magic twist angle have been imaged using angle-resolved photoemission spectroscopy.

Electronic rotons and Wigner crystallites have been observed experimentally and numerically in a two-dimensional dipole liquid.

In a topological insulator, the surface-state electron spins are ‘locked’ to their direction of travel. But when an electron is kicked out by a photon through the photoelectric effect, the spin polarization is not necessarily conserved. In fact, the ejected spins can be completely manipulated in three dimensions by the incident photons.

A microfocused angle-resolved photoemission spectroscopy study of single layers of WS₂ on hexagonal boron nitride reveals that, upon electron doping, trionic interactions cause a giant increase of the spin splitting in the valence band.

The identification of dark states—quantum states that do not interact with photons—in real materials may help to address many unsolved issues in condensed-matter physics. Now, they have been identified in palladium diselenide.

Analysis of HbA1c and FPG levels across 117 population-based studies demonstrates regional variation in prevalence of previously undiagnosed screen-detected diabetes using one or both measures and suggests that use of elevated FPG alone could underestimate diabetes prevalence in low- and middle-income countries.

Here, the authors report the observation of an interlayer plasmon polaron in heterostructures composed of graphene and monolayer WS₂. This is manifested in the ARPES spectra as a strong quasiparticle peak accompanied by several carrier density-dependent shake-off replicas around the WS₂ conduction band minimum.

Topological states in atomically thin quantum spin Hall insulators suffer from instability against environmental factors. Here, the authors devise a strategy to preserve topologically protected states in monolayer indenene through graphene intercalation.

Using valley-resolved scanning tunnelling spectroscopy, twisted WSe₂ bilayers are studied, including incommensurate dodecagon quasicrystals at 30° and commensurate moiré crystals at 21.8° and 38.2°.

Electrons in f orbitals can create localized states that interact strongly and drive strange metal and critical behaviour via the Kondo mechanism. Now a mechanism of geometric frustration enables similar phenomena with d electrons.

Reversible and rapid switching between metallic and insulating states is key for next-generation memory devices, but identifying and studying such materials is challenging. Here, using angle-resolved photoemission spectroscopy, the authors investigate a metastable metallic state of 1T-TaS₂ when exposed to short current pulses.

Angle-resolved photoemission spectroscopy of CaNi₂ shows a band with vanishing dispersion across the full 3D Brillouin zone that is identified with the pyrochlore flat band as well as two additional flat bands that arise from multi-orbital interference of Ni d-electrons.

The presence of excitonic instability and its relationship with a structural transition in Ta₂NiSe₅ has been debated. Chen et al. map out the electronic bands and lattice distortion across the semimetal-to-semiconductor transition with sulfur doping, revealing the crucial role of electron-phonon coupling.

The tunability of electronic properties is a central goal of research into topological semimetals. Here, the authors report Weyl nodal ring states in the magnetic semimetal EuGa₄ and link the nodal ring state to the observed large non-saturating magnetoresistance.

A prototypical kagome metal with magnetic and topological properties is identified.

The observation of band structure features typical of the kagome lattice in FeGe suggests that an interplay of magnetism and electronic correlations determines the physics of this material.

The authors use high-resolution angle-resolved photoemission spectroscopy to determine the microscopic structure of three-dimensional charge order in AV₃Sb₅ (A = K, Rb, Cs) and its interplay with superconductivity.

Analysis of the antiferromagnetic ordered phase of kagome lattice FeGe suggests that charge density wave is the result of a combination of electronic-correlations-driven antiferromagnetic order and instability driven by van Hove singularities.

The authors present evidence suggesting that amorphous Bi₂Se₃ displays topological properties, signalling a new regime for the pursuit of topological matter.

Films of the correlated oxide NdNiO₃ form a metallic antiferromagnetic phase that can be identified using electrical currents, raising the prospect of applications in spintronics.

A back-bending band structure and an emerging pseudogap are observed at the interface between a crystalline solid (black phosphorus) and disordered alkali-metal dopants.

Spectroscopic measurements show how the features of the band structure related to the kagome lattice in CsV₃Sb₅ contribute to the observed strongly correlated phases.

From 1980 to 2018, the levels of total and non-high-density lipoprotein cholesterol increased in low- and middle-income countries, especially in east and southeast Asia, and decreased in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe.

Single-crystal 2D metals are stabilized at the interface between epitaxial graphene and silicon carbide, with strong internal gradients in bonding character. The confined 2D metals demonstrate compelling superconducting properties.

The experimental realization of lattice-born flat bands with nontrivial topology has been elusive. Here, the authors observe topological flat bands near the Fermi level in a kagome metal CoSn, with flat bands as well as Dirac bands originating from 3d orbitals in a frustrated kagome geometry.

Whole-genome sequencing analysis of individuals with primary immunodeficiency identifies new candidate disease-associated genes and shows how the interplay between genetic variants can explain the variable penetrance and complexity of the disease.

Contrary to the view that urbanization is a major driver of the global rise in obesity, the global increase in body-mass index is shown to be mostly due to increases in the body-mass indexes of rural populations.

Anisotropic honeycomb crystal of black phosphorous is found to have pseudospin polarization greater than 95% at room temperature, attributed to the merging of Dirac cones. This bipolar pseudospin semiconductor may be useful for pseudospintronics.

Fe₃Sn₂ hosts massive Dirac fermions, owing to the underlying symmetry properties of the bilayer kagome lattice in the ferromagnetic state and the atomic spin–orbit coupling.

The physical properties of a solid-state material depends on its electronic structure, which can be studied using angle-resolved photoemission spectroscopy (ARPES). This Primer introduces the ARPES technique and describes how different variants can be used for applications including superconductors, topological materials and two-dimensional materials.

Doping is a tried and tested method to tune the properties of a range of quantum materials either by introducing defects into the system or engineering the charge carrier concentration. Here, the authors use photoemission spectroscopy to investigate the effects of surface doping of alkali metals on the Mott insulator Ca₂RuO₄, revealing an orbital-selective surface metal-insulator transition induced by the surface-dopant interaction.