Electron Density Response to Phonon Dynamics in MgB2: An Indicator of Superconducting Properties

摘要: Electron density differences resulting from atom displacement patterns aligned with phonon modes in MgB2 have been calculated using functional theory (DFT). The extent of anomalies, identified as indicators the superconducting transition temperature, Tc, under a range conditions AlB2-type structures, reduce boron atoms are displaced their equilibrium positions along E2g mode directions. Fermi energy for displacements directions accounts changes covalent B-B bond electronic charge density. We applied differential to show that shifted σ band structure associated light effective mass became tangential level and surface undergoes topological at critical relative ~0.6% equilibrium. difference energies this position correspond gap. net volume between tubular surfaces reciprocal space correlated depth anomaly and, by inference, it is key an understanding superconductivity. This ab initioapproach offers phenomenological factors determine Tc based on knowledge crystal structure.