Thickness- and Twist-Angle-Dependent Interlayer Excitons in Metal Monochalcogenide Heterostructures.

Interlayer excitons, or bound electron-hole pairs whose constituent quasiparticles are located in distinct stacked semiconducting layers, are being intensively studied in heterobilayers of two-dimensional semiconductors. They owe their existence to an intrinsic type-II band alignment between both layers that convert these into p-n junctions. Here, we unveil a pronounced interlayer exciton (IX) in heterobilayers of metal monochalcogenides, namely, γ-InSe on ε-GaSe, whose pronounced emission is adjustable just by varying their thicknesses given their number of layers dependent direct band gaps.

The Magnetic Genome of Two-Dimensional van der Waals Materials.

Magnetism in two-dimensional (2D) van der Waals (vdW) materials has recently emerged as one of the most promising areas in condensed matter research, with many exciting emerging properties and significant potential for applications ranging from topological magnonics to low-power spintronics, quantum computing, and optical communications. In the brief time after their discovery, 2D magnets have blossomed into a rich area for investigation, where fundamental concepts in magnetism are challenged by the behavior of spins that can develop at the single layer limit. However, much effort is still needed in multiple fronts before 2D magnets can be routinely used for practical implementations.

Early Response is Associated With Stable Long-Term Response in Psoriasis Patients Receiving Ixekizumab or Ustekinumab.

Background: The identification of early treatment factors that predict the long-term success of maintenance therapy for psoriasis may help optimize individual therapy.

Objective: To determine early treatment response rates to ixekizumab and ustekinumab and assess whether early response was associated with stable long-term response to these treatments in patients with moderate-to-severe psoriasis.

Methods: This post hoc subgroup analysis of the IXORA-S study (NCT02561806) measured disease severity using the Psoriasis Area Severity Index (PASI) and determined the percentage of patients treated with ixekizumab or ustekinumab who showed PASI 50 at week 2 or 4 (early response) and assessed whether early response was associated with maintaining complete (PASI 100) or almost complete (PASI 90) skin clearance at 80% of monthly visits during weeks 16−52 of treatment (stable response).

Properties and dynamics of meron topological spin textures in the two-dimensional magnet CrCl.

Merons are nontrivial topological spin textures highly relevant for many phenomena in solid state physics. Despite their importance, direct observation of such vortex quasiparticles is scarce and has been limited to a few complex materials. Here, we show the emergence of merons and antimerons in recently discovered two-dimensional (2D) CrCl at zero magnetic field.

Quantum Rescaling, Domain Metastability, and Hybrid Domain-Walls in 2D CrI Magnets.

Higher-order exchange interactions and quantum effects are widely known to play an important role in describing the properties of low-dimensional magnetic compounds. Here, the recently discovered 2D van der Waals (vdW) CrI is identified as a quantum non-Heisenberg material with properties far beyond an Ising magnet as initially assumed. It is found that biquadratic exchange interactions are essential to quantitatively describe the magnetism of CrI but quantum rescaling corrections are required to reproduce its thermal properties.

Ultrahigh-current-density niobium disulfide catalysts for hydrogen evolution.

Metallic transition metal dichalcogenides (TMDs) are good catalysts for the hydrogen evolution reaction (HER). The overpotential and Tafel slope values of metallic phases and edges of two-dimensional (2D) TMDs approach those of Pt. However, the overall current density of 2D TMD catalysts remains orders of magnitude lower (~10-100 mA cm) than industrial Pt and Ir electrolysers (>1,000 mA cm).