Implementing electronic signatures of graphene and hexagonal boron nitride in twisted bilayer molybdenum disulfide

<p><strong>Abstract</strong></p> <p>Angeli and MacDonald reported a superlattice-imposed Dirac band in twisted bilayer molybdenum disulphide (tBL MoS2) for small twist angles towards the R_h^M (parallel) stacking. Using a hierarchical set of theoretical methods, we show that the superlattices differ for twist angles with respect to metastable R_h^M (0&deg;) and lowest-energy H_h^h (60&deg;) configurations. When approaching R_h^M stacking, identical domains with opposite spatial orientation emerge. They form a honeycomb superlattice, yielding Dirac bands and a lateral spin texture distribution with opposite-spin-occupied K and K&rsquo; valleys. Small twist angles towards the H_h^h configuration (60&deg;) generate H_h^h and H_h^X stacking domains of different relative energies and, hence, different spatial extensions. This imposes a symmetry break in the moir&eacute; cell, which opens a gap between the two top-valence bands, which become flat already for relatively small moir&eacute; cells. The superlattices impose electronic superstructures resembling graphene and hexagonal boron nitride into trivial semiconductor MoS₂.</p> <p>The data set published in this repository was used to create the preprint published at <strong>https://doi.org/10.26434/chemrxiv-2023-rx2fz</strong>.</p> <p><strong>Content of repository</strong></p> <ul> <li>&quot;ReaxFF_structure_optimization.zip&quot;: contains the inputs and outputs for all structure optimizations for ML, BL, and tBL systems using the Reax force field, performed using LAMMPS.</li> <li>&quot; bilayer_verification_ReaxFF_with_DFT.zip&quot;: contains the inputs and outputs for verifying the results of the Reax force field by running DFT geometry optimization and total energy calculations in FHI-aims for the high-symmetry bilayer stackings.</li> <li>&quot;QATK_band_structures_and_eff_mass.zip&quot;: contains the inputs and outputs of all calculations done via QuantumATK (QATK), including calculations for ML, BL, and tBL systems on DFT and DFTB level of theory.</li> <li>&quot;TB_fit.zip&quot;: contains the Python scripts and input data (DFTB band structure) used to fit the TB Hamiltonians as described in the Methods section and shown in the Supplementary Material.</li> <li>&quot;effective_masses_from_bands.zip&quot;: contains the extraction of the effective hole masses from the bands calculated at the DFTB level of theory in QATK.</li> </ul>