The realization of large and tunable Zeeman splitting and the effective g factor is key for spin control in spintronics and quantum information processing. Although marked Zeeman splitting and effective g factor have been demonstrated in GaAs1-xBix nanowires, the effects of nitrogen incorporation and uniaxial stress on the Zeeman effect remain unexplored. In view of this, the electronic structure and Zeeman splitting characteristics of cylindrical GaAs1-x-yNxBiy nanowires under an axial magnetic field and uniaxial tensile stress are systematically investigated, using a combination of the effective-mass theory with the valence-band anticrossing and conduction-band anticrossing models. The calculation results show that dilute nitrogen incorporation has a minimal effect on the Zeeman splitting, whereas uniaxial tensile stress applied along the [001] direction leads to an exponential increase in the Zeeman splitting energy. At U 001 = 6 GPa, the splitting energy and effective g factor are enhanced nearly twofold relative to their unstrained values. Moreover, the simulated normalized magnetic circular dichroism spectra provide further evidence for the observed trends in spectral features and Zeeman splitting. These findings highlight the significant potential of GaAs1-x-yNxBiy nanowires as a platform for quantum information processing.
By employing first‐principles‐assisted CALYPSO structural exploration combined with high‐pressure thermodynamic analysis, this study systematically establishes the phase diagram of the binary Li–Ce system within the 200, 300, and 350 GPa pressure regime. The LiCe phase is identified as metastable at 200 GPa; however, upon further compression to 300 and 350 GPa, it transforms into a thermodynamically stable state. Electronic structure calculations reveal that extreme compression enhances orbital hybridization and electron delocalization, thereby reinforcing the metallic character of the phase. Furthermore, superconducting analysis uncovers a superconductivity mechanism driven by the synergistic coupling between Ce and Li phonon modes. With increasing pressure, the electron–phonon coupling mechanism gradually shifts from being dominated by low‐frequency heavy‐atom (Ce) modes toward enhanced participation of high‐frequency light‐atom (Li) modes. Consequently, the superconducting critical temperatures ( T c ) of the LiCe phase are calculated to be 3.04, 0.48 and 0.23 K at 200, 300 and 350 GPa, respectively.
While two‐dimensional group‐V binary nanoribbons hold promise for spintronics, the synergistic effects of edge configuration and elemental substitution on their spin‐polarized transport remain unclear. Here, we combine density functional theory (DFT) and the nonequilibrium Green’s function (NEGF) method to investigate β‐NP and β‐NBi nanoribbons. Heyd–Scuseria–Ernzerhof (HSE06) hybrid functional calculations correct the spurious spin‐polarized generalized gradient approximation (SGGA) half‐metallicity, confirming that all systems are intrinsically semiconducting. We demonstrate that zigzag edges induce strong localized spin‐polarized states via symmetry breaking, whereas armchair edges exhibit weak spin splitting. Crucially, transport simulations reveal that orbital symmetry matching and transmission spectra govern the macroscopic spin‐filtering efficiency (SFE). Armchair NP achieves near‐perfect SFE (>95%) but yields sub‐microampere currents due to a severe transmission blockade, while zigzag NP suffers from unstable dual‐spin competition. In the heavier NBi series, armchair NBi is practically insulating. However, zigzag NBi perfectly balances stability and efficiency: it opens a clean transmission gap to strictly suppress the spin‐up channel, delivering stable single‐spin transport with high SFE (>94%) over most of the bias range and an appreciable current (~0.23 μA). Ultimately, while edge symmetry initiates spin polarization, heavy‐element substitution dictates its conversion into robust filtering currents, providing clear design guidelines for intrinsic 2D spintronic devices.
A variety of new atomic models for the Si(111) 7 × 7 surface are created and optimized using density functional theory (DFT) calculations and evaluated against a diversity of experimental measures to understand the paradoxes found for the widely accepted dimer‐adatom‐stacking‐fault (DAS) reconstruction model. These include registry‐shifted adlayers, different termination layers, additional atoms, missing dimers or dumbbell atoms within distorted honeycomb (HC) or silicene‐like structures. Their geometric and electronic structures are evaluated with and without spin polarization using DFT and the approximate quasiparticle DFT‐1/2 scheme and show that several new allotropes agree with various experimental features better than DAS. Calculated formation energies are used to construct a phase diagram as a function of silicon's chemical potential, which favors DAS, but only for bulk‐like atom reservoirs, while other geometries are favored for modified substrate chemical potentials. Surface band gaps are found for magnetic phases of most and/or a few nonmagnetic allotropes. The overall best qualitative agreement with experiment is found for a magnetic phase that unlike DAS has a significant laterally distorted HC with high‐ and low‐buckled adatoms on the two sides of the unit cell. The nature of this structure and interactions that drive this new class of reconstruction are discussed.
Leveraging the unique composite effect arising from its multielement composition, the multielement cathode material effectively mitigates the inherent limitations of conventional ternary cathode materials, such as structural degradation, insufficient thermal stability, and interfacial side reactions, thereby opening new avenues for the structural design and performance optimization of high‐performance cathode materials. However, current research on this strategy remains largely reliant on trial‐and‐error, result‐oriented experimental approaches, which are associated with lengthy development cycles and high costs. Consequently, there is an urgent need to incorporate theoretical calculations and simulation methods to provide theoretical guidance for the rational design of multielement cathode materials. In this study, using density functional theory, we systematically investigate the structural and electronic property variations in multielement cathode materials, aiming to elucidate the mechanisms by which multicomponent synergistic interactions influence material stability. This work provides a theoretical foundation for the design and optimization of elemental compositions in multielement cathode materials.
