EDITORS' SUGGESTION
Low or quasi reduced-dimensional crystal structures are associated with enhanced electronic correlations and emergent quantum behavior. Despite wide interest, identification of new material examples remains restricted by the lack of chemical rules for predicting the structure of extended solids. The authors present the antagonistic pairs approach to discover intermetallic compounds with reduced dimensional structural motifs. By using a pair of strongly immiscible atoms (an antagonistic pair) with a mutually compatible third element, they show that ternary compounds can be formed in which the compatible third element separates the immiscible elements into distinct crystallographic substructures. Quasi-low dimensional structural units, such as sheets, chains, or clusters are the consequence of the immiscible atoms trying to avoid close contact in the solid state. As an example, the authors outline the discovery of LaCo ( = Pb, Bi, Sb), a family of intermetallic compounds in which the La separates the highly immiscible Co-Pb or Co-Bi atoms into a quasi-layered structure. They anticipate that their approach is a generalizable design principle for discovering new materials and new structure types containing low-dimensional substructures.
Tyler J. Slade et al.
Phys. Rev. Materials 8, 064401 (2024)
EDITORS' SUGGESTION
Inspired by the nonmagnetic topological materials database, the authors investigated the 3D fermiology and band topology of the Topological Crystalline Insulator (TCI) candidate SrAgSb. The fermiology, revealed by angular-dependent quantum oscillations, shows excellent agreement with first-principles calculations. Symmetry and topology analysis result in two potential sets of topological invariants, suggesting the emergence of crystal-symmetry-protected gapless Dirac surface states either on the as-grown ab planes or on both the ab planes and as-grown mirror planes. Their findings provide evidence that SrAgSb is a promising TCI for exploring topological surface states protected by crystal symmetry.
J. Green et al.
Phys. Rev. Materials 8, 054205 (2024)
EDITORS' SUGGESTION
A reliable interlayer band structure of the kagome superconductor CsVSb is critical for understanding emergent phenomena like the charge density wave ordering and for classifying the topology. Here, the authors present a survey of computational techniques aimed at comparing the electronic interactions between kagome layers in CsVSb. This study highlights the computational parameters and plotting methods that lead to differing band behaviors. Within conventional DFT, the parameters employed during structural relaxation are critical in determining the electronic structure between kagome layers. However, higher levels of computational theory contrast these results and point to the increased role of interlayer interactions.
Aurland K. Watkins et al.
Phys. Rev. Materials 8, 054204 (2024)
EDITORS' SUGGESTION
The study focuses on the systematic growth and characterization of material properties, as well as the low-temperature transport properties, of ultrashallow heavily strained quantum wells. A new characterization method, called Density of Stress Accumulation Points, has been introduced for assessing quantum well strain. An ultrashallow heavily constrained quantum well with a remarkable mobility of 3.382×105 cm/Vs was successfully achieved. This achievement serves as the foundation for the development of fully electrically controlled and microwave cavity-coupled quantum dot materials.
Yiwen Zhang et al.
Phys. Rev. Materials 8, 046203 (2024)
EDITORS' SUGGESTION
In this work, we investigate the effect of strong disorder on BixTeI thin films, revealing a metal-insulator transition that depends on composition and the growth temperature. Understanding how disorder can be used as a parameter to alter the electronic properties of a material goes beyond the conventional understanding of crystalline material conductivity. This study therefore highlights the role of strong localization in disordered materials in shaping emerging quantum properties.
Paul Corbae et al.
Phys. Rev. Materials 8, 044204 (2024)
EDITORS' SUGGESTION
The authors computed bandgaps and formation energy values of more than 1100 crystalline materials using Density Functional Theory (DFT) with HSE and PBE approximations of the pseudopotentials. They analyzed accuracies of HSE and PBE approximations among different classes of materials. They also built a multi-fidelity machine learning model to predict the bandgap at HSE accuracy when a material’s PBE bandgap is known. The new high-throughput DFT (HSE, PBE) data of more than 1100 materials and the predicted HSE bandgap data of more than 21,000 materials are available publicly via a dedicated web app.
Mohan Liu et al.
Phys. Rev. Materials 8, 043803 (2024)
EDITORS' SUGGESTION
α-Sn, the inversion symmetric analogue of HgTe, can be tuned through various topologically non-trivial phases by a combination of strain and/or confinement effects. In addition, thin films of α-Sn have demonstrated very efficient spin-charge conversion. However, α-Sn thin films grown on InSb have been plagued by heavy incorporation of the p-type dopant indium. To better study and make use of the topological phases in α-Sn, this indium doping must be minimized. The authors realize this reduction by tuning the surface reconstruction of InSb(001) on which molecular beam epitaxy growth of α-Sn is initiated. The low indium doping is verified by both photoemission and magnetotransport measurements. The accessibility of the surface Dirac node in angle-resolved photoemission spectroscopy—made possible by the substrate preparation procedure—allows direct measurements of the effect of confinement and epitaxial strain on the topological phase in this system.
Aaron N. Engel et al.
Phys. Rev. Materials 8, 044202 (2024)