Seminár z fyziky kondenzovaných látok - Marius Kadek (20.6.2023)

v utorok 20.6.2023 o 14:00 v posluchárni F2 272

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Prednášajúci: Dr. Marius Kadek (Hylleraas Centre for Quantum Molecular Sciences, UiT The Arctic University of Norway, Tromsø, Norway)

Názov: First-principles modelling of 2D materials using relativistic all-electron Dirac-Kohn-Sham theory based on Gaussian-type orbitals

Termín: 20.6.2023, 14:00 hod., F2/272

Abstrakt:
Two-dimensional (2D) materials, such as the transition-metal dichalcogenide (TMDs) films, are currently drawing intense interest from the materials community because they exhibit a wide range of remarkable properties, many of which are driven by strong spin--orbit coupling (SOC) effects that arise from the presence of heavy elements. Using Gaussian-type orbitals (GTOs) for treating electronic structures of 2D materials offers several advantages. First, the all-electron nature of the basis set opens avenues for the application of a range of methods common in quantum chemistry to allow a handle on the interaction of nuclear spins with electrons (needed for instance for spin Hamiltonian parameters) and accurate modeling of electron correlation effects. Second, techniques based on local basis functions can exploit algorithms that scale linearly with the system size enabling treatment of structures with large complicated unit cells. Third, adopting the GTO atom-centered basis, 2D materials can be studied without the need to introduce periodic images of the system in the direction perpendicular to the 2D plane, in contrast to the case when plane waves are employed. I will discuss a methodology for efficient and stable convergence of the electronic band structures of various phases of 2D TMDs using the four-component Dirac-Coulomb Hamiltonian and investigate large spin-orbit-induced splittings and the quantum spin-Hall effect found in TMDs.

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