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In twisted 2D materials, spontaneous lattice reconstructions mean that twist angle alone provides an incomplete description. Here, using electron diffraction, the authors show that the displacement field in twisted bilayer graphene can be described as a superposition of three periodic lattice distortion (PLD) waves with wavevectors oriented at 120° from each other, forming a “torsional" PLD.

Examination of a complete structural phase diagram of twisted trilayer graphene shows that several large-scale moiré domain lattices can be formed, the physical properties of which can be tuned by the twist angles between layers.

Double-sided epitaxy of van der Waals materials through atomic membranes is demonstrated, enabling electrons to resonantly tunnel between aligned topological insulator surfaces with the conservation of energy, momentum and spin helicity.

Domain-resolved spectroscopy reveals the impact of local atomic registry and crystal symmetry on the exciton properties of individual domains in near-0°-twist-angle MoSe₂/MoSe₂.

Polar domains have been observed in twist-stacked van der Waals layers, but their dynamics are unexplored. Here, using operando electron microscopy, it is found that polar domains in an antiferroelectric arrangement cannot transition to a ferroelectric state due to topological protection of the domain wall network.

Recent studies have revealed unexpected characteristics in moiré superlattices formed by stacking two-dimensional crystals. Here, the authors report whirlpool-shaped periodic lattice distortions in moiré superlattices leading to anomalous optical responses.

Twisted double bilayer graphene devices show tunable spin-polarized correlated states that are sensitive to electric and magnetic fields, providing further insights into correlated states in two-dimensional moiré materials.

The in-situ growth of epitaxial GaN with a short-range ordered (SRO) BN interlayer is proposed to demonstrate a high manufacturing scalability of the epitaxial lateral overgrowth (ELOG) process. During the GaN growth, the mask formation of the SRO BN occurred in the on-site chamber within a few minutes. The BN interlayer efficiently reduced microstructural defects, such as screw-type and edge-type threading dislocations, to achieve high structural and optical characteristics of the GaN overlayer, whose results are comparable to those of the previously reported ex-situ ELOG approaches. These improvements were also demonstrated in the device performances of the GaN light-emitting diodes.

The electrointercalation of lithium into van der Waals heterostructures of graphene, hexagonal boron nitride and molybdenum dichalcogenides is studied at the level of individual atomic interfaces.

An investigation of the structural and transport properties of bilayer graphene as a function of the twist angle between the layers reveals atomic-scale reconstruction for twist angles smaller than a critical value.

The effects of structural relaxation (SR) on the electronic state of oxygen vacancies (V_O s) in amorphous oxide semiconductors is investigated. Without redox reactions, the concentration of V_O s in the shallow-donor state (N_DS) increases about 10³ times with increases in the annealing temperature from 300 to 450 °C. The reduction in the free volume size and transformation of V_O s in either deep-donor or electron-trap states into the shallow-donor state during SR is the primary mechanism responsible for the increase in N_DS.