153 citations · 526 across the 22 of their papers we have counts for
23 papers
Excitons in Large Disordered Boron-Nitride Layer using Linear-Scaling Bethe-Salpeter Simulations
Thomas Galvani, Lorenzo Sponza, Hakim Amara +2
We introduce a real-space, linear-scaling Bethe-Salpeter framework that enables excitonic spectroscopy in large and possibly disordered boron-nitride-derived systems. Thanks to the…
Surface reconstruction-driven band folding and spin-orbit enhancement at the -antimonene/Au(111) interface
Thomas Pierron, José de Jesùs Villalobos Castro, Etienne Barre +9
The electronic properties of the two-dimensional (2D) phase of antimonene are unique, featuring unpinned Dirac cones that can be moved with strain. Here we investigate the stru…
Selective band engineering of Bi/Si(111) by boron segregation
E. Barre, J. Villalobos-Castro, T. Pierron +4
Atomically thin layers of metals deposited on semiconductors display a variety of physical properties such as superconductivity, charge density waves, topological phases, strong sp…
First-principle investigation of the electronic structure and optical properties of graphene/boron nitride lateral heterostructures
Elisa Serrano Richaud, Sylvain Latil, Lorenzo Sponza
We investigate the electronic and optical properties of lateral heterostructures made of alternated armchair ribbons of graphene and hexagonal boron nitride. It is known that the g…
Three-dimensional deformations in single-layer antimonene and interaction with a Au(111) surface from first principles
José de Jesús Villalobos Castro, Thomas Pierron, Stephane Pons +3
Using density functional theory, we investigate the electronic structure of the alpha phase of an antimony monolayer in its isolated form and in contact to the (111) surface of gol…
Emergence of flat bands in the quasicrystal limit of boron nitride twisted bilayers
Lorenzo Sponza, Van Binh Vu, Elisa Serrano Richaud +2
We investigate the electronic structure and the optical absorption onset of close-to-30\degree twisted hexagonal boron nitride bilayers. Our study is carried out with a purposely d…
Distinguishing different stackings in layered materials via luminescence spectroscopy
Matteo Zanfrognini, Alexandre Plaud, Ingrid Stenger +10
Despite its simple crystal structure, layered boron nitride features a surprisingly complex variety of phonon-assisted luminescence peaks. We present a combined experimental and th…
Gap engineering and wave function symmetry in C and BN armchair nanoribbons
Elisa Serrano Richaud, Sylvain Latil, Hakim Amara +1
Many are the ways of engineering the band gap of nanoribbons including application of stress, electric field and functionalization of the edges. In this article, we investigate sep…
Quantum well confinement and competitive radiative pathways in the luminescence of black phosphorus layers
Etienne Carré, Lorenzo Sponza, Alain Lusson +8
Black phosphorus (BP) stands out from other 2D materials by the wide amplitude of the band-gap energy (Delta(Eg)) that sweeps an optical window from Visible (VIS) to Infrared (IR)…
Structural classification of boron nitride twisted bilayers and ab initio investigation of their stacking-dependent electronic structure
Sylvain Latil, Hakim Amara, Lorenzo Sponza
Since the discovery of superconductive twisted bilayer graphene which initiated the field of twistronics, moiré systems have not ceased to exhibit fascinating properties. We demons…
Radiative lifetime of free excitons in hexagonal boron nitride
Sébastien Roux, Christophe Arnold, Fulvio Paleari +12
Using a new time-resolved cathodoluminescence system dedicated to the UV spectral range, we present a first estimate of the radiative lifetime of free excitons in hBN at room tempe…
Proper ab-initio dielectric function of 2D materials and their polarizable thickness
Lorenzo Sponza, François Ducastelle
In this paper we derive a formalism allowing us to separate inter-layer contributions to the polarizability of a periodic array of 2D materials from intra-layer ones. To this aim,…
Excitons in bulk black phosphorus evidenced by photoluminescence at low temperature
Etienne Carré, Lorenzo Sponza, Alain Lusson +4
Atomic layers of Black Phosphorus (BP) present unique opto-electronic properties dominated by a direct tunable bandgap in a wide spectral range from visible to mid-infrared. In thi…
The impact of stress on the electronic structure of phosphorus allotropes stacked on hexagonal boron nitride
Baptiste Bienvenu, Hakim Amara, François Ducastelle +1
We study the mechanical and electronic properties of heterobilayers composed of black phosphorus (BP) on hexagonal boron nitride (hBN) and of blue phosphorus (\Pblue) on hBN by mea…
Evening out the spin and charge parity to increase T in unconventional superconductor Sr_{2}RuO_{4}
Swagata Acharya, Dimitar Pashov, Cédric Weber +3
Unconventional superconductivity in SrRuO has been intensively studied for decades. The origin and nature of the pairing continues to be widely debated, in particular,…
Mapping of the energetically lowest exciton in bulk -HfS
Carsten Habenicht, Lorenzo Sponza, Roman Schuster +2
By combining electron energy-loss spectroscopy and state-of-the-art computational methods, we were able to provide an extensive picture of the excitonic processes in -HfS.…
Direct and indirect excitons in boron nitride polymorphs: a story of atomic configuration and electronic correlation
Lorenzo Sponza, Hakim Amara, Claudio Attaccalite +5
We compute and discuss the electronic band structure and excitonic dispersion of hexagonal boron nitride (hBN) in the single layer configuration and in three bulk polymorphs (usual…
Bright luminescence from indirect and strongly bound excitons in hBN
Leonard Schue, Lorenzo Sponza, Alexandre Plaud +6
A quantitative analysis of the excitonic luminescence efficiency in hexagonal boron nitride (hBN) is carried out by cathodoluminescence in the ultraviolet range and compared with z…
Exciton interference in hexagonal boron nitride
Lorenzo Sponza, Hakim Amara, Claudio Attaccalite +2
In this letter we report a thorough analysis of the exciton dispersion in bulk hexagonal boron nitride. We solve the ab initio GW Bethe-Salpeter equation at finite $\mathbf{q}\para…
Angular resolved electron energy loss spectroscopy in hexagonal boron nitride
Frédéric Fossard, Lorenzo Sponza, Léonard Schué +4
Electron energy loss spectra have been measured on hexagonal boron nitride single crystals employing a novel electron energy loss spectroscopic set-up composed by an electron micro…
Confinement effects in ultra-thin ZnO polymorph films: electronic and optical properties
Lorenzo Sponza, Jacek Goniakowski, Claudine Noguera
Relying on generalized-gradient and hybrid first-principles simulations, this work provides a complete characterization of the electronic properties of ZnO ultra-thin films, cut al…
Exciton band structure in two-dimensional materials
Pierluigi Cudazzo, Lorenzo Sponza, Christine Giorgetti +3
Low-dimensional materials differ from their bulk counterpart in many respects. In particular, the screening of the Coulomb interaction is strongly reduced, which can have important…
Anomalous excitons and screenings unveiling strong electronic correlations in SrTiNbO, 0x0.005
Pranjal Kumar Gogoi, Lorenzo Sponza, Daniel Schmidt +8
Electron-electron (e-e) and electron-hole (e-h) interactions are often associated with many exotic phenomena in correlated electron systems. Here, we report an observation of anoma…