collaborators

5 papers

cond-mat.mtrl-sci2025

Ultraviolet optical conductivity, exciton fine-structure and dispersion of freestanding monolayer h-BN

Jinhua Hong, Alberto Guandalini, Weibin Wu +7

Excitons govern the light-matter interaction in 2D gapped materials with intrinsically large binding energies. In spite of plentiful optical measurements in the visible for semicon…

cond-mat.mes-hall2025

Infrared markers of topological phase transitions in quantum spin Hall insulators

Paolo Fachin, Francesco Macheda, Paolo Barone +1

Using first principles techniques, we show that infrared optical response can be used to discriminate between the topological and the trivial phases of two-dimensional quantum spin…

cond-mat.mtrl-sci2025

Excitonic effects in phonons: reshaping the graphene Kohn anomalies and lifetimes

Alberto Guandalini, Francesco Macheda, Giovanni Caldarelli +1

We develop an ab initio framework that captures the impact of electron-electron and electron-hole interactions on phonon properties. This enables the inclusion of excitonic effects…

cond-mat.mtrl-sci2024

Variational formulation of dynamical electronic response functions in presence of nonlocal exchange interactions

Giovanni Caldarelli, Alberto Guandalini, Francesco Macheda +1

We consider the dynamical electronic response function in theoretical frameworks that include nonlocal exchange interactions, such as the Bethe-Salpeter equation with the frequency…

physics.atm-clus2024

High- and low-energy many-body effects of graphene in a unified approach

Alberto Guandalini, Giovanni Caldarelli, Francesco Macheda +1

We show that the many-body features of graphene band structure and electronic response can be accurately evaluated by applying many-body perturbation theory to a tight-binding (TB)…