3 citations · 3 across the 12 of their papers we have counts for
13 papers
Unified description of exciton, phonon and plasmon dispersions in 2D materials from an optical conductivity approximation
Alberto Guandalini, Andrea Ferretti, Daniele Varsano +2
The modified Coulomb interaction in two-dimensional (2D) materials gives rise to unique, non-analytic low-momentum dispersions of excitons, phonons, and plasmons. Here, we describe…
The principle of detailed balance between electrons and phonons in presence of excitonic effects
Alberto Guandalini, Giovanni Caldarelli, Francesco Mauri +1
Based on a many-body formulation, we derive an electron-phonon coupling including excitonic effects that preserves thermodynamic detailed balance between electronic and phononic sc…
Effective single particle picture for anharmonic lattice dynamics: a Rosetta stone for electronic and ionic response
Giovanni Caldarelli, Francesco Mauri
We establish a theoretical framework for the dynamics of a lattice of ions in a mean-field approach, where anharmonicity is included via self-consistency. In this picture, the many…
Frequency-dependent electron-phonon coupling and vibrational responses in tight-binding and continuous Dirac models with nuclear velocity correction
Paolo Fachin, Francesco Macheda, Paolo Barone +1
The nuclear motion induces in the electronic atomic orbitals a nuclear-velocity-dependent phase (also known as electron-translation factor), which modifies the effective Hamiltonia…
Non-adiabatic Ehrenfest dynamics with norm-conserving and ultra-soft pseudo-potentials with nuclear velocity corrections on the atomic orbitals within the Projector Augmented Wave Method framework
Paolo Fachin, Francesco Macheda, Paolo Barone +1
We derive the first-principles Ehrenfest molecular dynamics describing non-adiabatic processes with the inclusion of the nuclear-velocity-dependent phases (also known as electron-t…
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…
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…
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…
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…
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)…
First principles calculations of dynamical Born effective charges, quadrupoles and higher order terms from the charge response in large semiconducting and metallic systems
Francesco Macheda, Paolo Barone, Francesco Mauri
Within the context of first principles techniques we present a theoretical and computational framework to quickly determine, at finite momentum, the self-consistent (longitudinal)…
Direct observation of the vanishing EELS cross section in graphene
Alberto Guandalini, Ryosuke Senga, Yung-Chang Lin +5
In transmission electron energy-loss spectroscopy, the cross section in 2D is quenched by kinematic effects once the momentum transfer becomes smaller than a critical value set by…
Quantized Born Effective charges as probes for the topological phase transition in the Haldane and Kane-Mele models
Paolo Fachin, Francesco Macheda, Paolo Barone +1
We propose a new approach to study the transition between different topological states, based on the assessment of the vibrational resonances in infrared spectra. We consider the H…