arXiv subjects

Ricardo Mendes Ribeiro

Publications and source records attributed to Ricardo Mendes Ribeiro.

2 recordsLinked to original sources

arXiv2023

Berry: A code for the differentiation of Bloch wavefunctions from DFT calculations

Density functional calculations of electronic structures of materials is one of the most used techniques in theoretical solid state physics. These calculations retrieve single electron wavefunctions and their eigenenergies. The berry suite of programs amplifies the usefulness of DFT by ordering the eigenstates in analytic bands, allowing the differentiation of the wavefunctions in reciprocal space. It can then calculate Berry connections and curvatures and the second harmonic generation conductivity. The berry software is implemented for two dimensional materials and was tested in hBN and InSe. In the near future, more properties and functionalities are expected to be added.

cond-mat.mes-hall↗

arXiv2017

Improvements in the $GW$ and Bethe-Salpeter-equation calculations on phosphorene

Phosphorene is a bidimensional material that has properties useful for semiconductor devices. In this work we studied the electronic and optical properties of this material using the $GW$ approximation and the Bethe-Salpeter equation (BSE) methods. We stress the importance of a careful convergence study of the most relevant parameters, and we show how they affect the result of the calculations. A comparison with previous results is given. The QP band gap obtained was 2.06 eV and it is in good agreement with experimental results. BSE calculations were performed on top of $G_0W_0$ to include excitonic effects. The absorption spectrum was analysed and an optical gap of 1.22 eV was obtained. The calculated excitonic binding energy is 0.84 eV, also in good agreement with experimental results.

cond-mat.mes-hall↗