20th Brazilian Workshop On Semiconductor Physics

Session

Oral

12 sept. 2022, 09:50

Instituto Tecnológico de Aeronáutica

Documents de présentation

Abstract1-YGG-BWSP_20th-last - Yara Galvão Gobato.pdf

22. Optical Properties of Moiré excitons in WS2 -MoSe2 heterostructures

Prof. Yara Galvão Gobato (Physics Department - Federal University of São Carlos)

12/09/2022 09:50

Abstract

Twisted van der Waals (vdW) heterostructures exhibit periodic variations, leading to a new type of in-plane superlattice known as moiré superlattice/pattern which modifies considerably the optical properties of excitons in transition metal dichalcogenides (TMD) vdW heterostructures. The period of these moiré superlattices is determined by the lattice constant mismatch and the twist...

20. Effective kp Hamiltonians calculated from ab initio data

Prof. G. J. Ferreira (Instituto de Física - Universidade Federal de Uberlândia)

Abstract

In this talk we will present a new code, called QE2KP, which calculates the effective kp Hamiltonian using the ab initio wave-functions as basis functions to calculate the matrix elements of the kp theory within the Löwdin perturbation approach. The kp method is widely used to obtain effective Hamiltonians to describe a chosen set of bands of crystalline materials. The derivation...

27. Magnetotransport measurements for detection of Dirac fermions in topological insulators

Prof. Marcelos L. Peres (Instituto de Física e Química - Universidade Federal de Itajubá)

Abstract

Topological insulators (TIs) are materials that are insulating in their bulk but present metallic states on their surface. This is the simplest definition for a complex quantum effect that results from strong spin-orbit coupling that changes the topological order of the material. The metallic states host spin-polarized currents composed of Dirac fermions flowing on the topological...

23. To be defined

Prof. Andreia Luisa da Rosa (Universidade Federal de Goiás)

Abstract

We carried out first-principles density functional theory calculations of hydrogen and oxygen adsorption and diffusion on subnanometer MoS nanowires. The nanowires are robust against adsorption of hydrogen. On the other hand, interaction with oxygen shows that the nanowires can oxidize with a small barrier. Our results open the path for understanding the behavior of MoS nanowires...