Publications related to Surface states

Realization of an atomic quantum Hall system in four dimensions

Modern condensed matter physics relies on the concept of topology to classify matter, from quantum Hall systems to topological insulators. Engineered systems, benefiting from synthetic dimensions, can potentially give access to topological states predicted ...

American Association for the Advancement of Science2024

Data-Intensive Exploration of the Photoelectrochemical Responses of Main-Group Metal Sulfides

Nicola Colonna

Materials that efficiently promote the thermodynamically uphill water-splitting reaction under solar illumination are essential for generating carbon-free ("green") hydrogen. Mapping out the combinatorial space of potential photocatalysts for this reaction ...

Amer Chemical Soc2024

High-Quality Data Enabling Universality of Band Gap Descriptor and Discovery of Photovoltaic Perovskites

Alfredo Pasquarello, Haiyuan Wang, Wei Chen

Extensive machine-learning-assisted research has been dedicated to predicting band gaps for perovskites, driven by their immense potential in photovoltaics. Yet, the effectiveness is often hampered by the lack of high-quality band gap data sets, particular ...

Amer Chemical Soc2024

High-throughput screening of Weyl semimetals

Nicola Marzari, Davide Grassano, Davide Campi

Topological Weyl semimetals represent a novel class of nontrivial materials, where band crossings with linear dispersions take place at generic momenta across reciprocal space. These crossings give rise to low -energy properties akin to those of Weyl fermi ...

Amer Physical Soc2024

Automated all-functionals infrared and Raman spectra

Nicola Marzari, Lorenzo Bastonero

Infrared and Raman spectroscopies are ubiquitous techniques employed in many experimental laboratories, thanks to their fast and non-destructive nature able to capture materials' features as spectroscopic fingerprints. Nevertheless, these measurements freq ...

Nature Portfolio2024

A remarkable new Agestrata Eschscholtz, 1829 from Myanmar (Coleoptera, Scarabaeidae, Cetoniinae)

Michele De Palma

A new species in the genus Agestrata Eschscholtz, 1829 is described from Myanmar. The new taxon, Agestrata fortii n. sp., is markedly different from the other members of the genus. Further to the uniform turquoise-cerulean blue color of the integument, A. ...

2023

Unraveling the Effect of the Chemical and Structural Composition of ZnxNi1-xFe2O4 on the Electron Transfer at the Electrochemical Interface

Sandro Carrara, Mallikarjun Madagalam

In order to deepen the understanding of the role of transition metal oxides in electron transfer at the electrochemical interface, the performance of ZnxNi1-xFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) nanomaterials in electrochemical sensing is studied. Nanomate ...

WILEY2023

Origin of metallic-like behavior in disordered carbon nano-onions

Oleg Yazyev, Kristians Cernevics

Carbon nano-onions are a class of nanomaterials that can exhibit long electron spin relaxation times at room temperature and thus hold promise as potential building blocks for spintronics and quantum information processing devices. Despite first being synt ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Complementary screening for quantum spin Hall insulators in two-dimensional exfoliable materials

Nicola Marzari, Antimo Marrazzo, Davide Grassano, Davide Campi

Quantum spin Hall insulators are a class of topological materials that has been extensively studied during the past decade. One of their distinctive features is the presence of a finite band gap in the bulk and gapless, topologically protected edge states ...

Amer Physical Soc2023

Character of Electronic States in the Transport Gap of Molecules on Surfaces

Klaus Kern, Abhishek Grewal

We report on scanningtunneling microscopy (STM) topographs ofindividual metal phthalocyanines (MPc) on a thin salt (NaCl) filmadsorbed on a gold substrate, at tunneling energies within the molecule'selectronic transport gap. Theoretical models of increasin ...

AMER CHEMICAL SOC2023

Magnon-phonon interactions enhance the gap at the Dirac point in the spin-wave spectra of CrI3 two-dimensional magnets

Iurii Timrov

Recent neutron-diffraction experiments in honeycomb CrI3 quasi-2D ferromagnets have evinced the existence of a gap at the Dirac point in their spin-wave spectra. The existence of this gap has been attributed to strong in-plane Dzyaloshinskii-Moriya or Kita ...

2023

Spin, Charge, and ?-Spin Separation in One-Dimensional Photodoped Mott Insulators

Philipp Georg Werner Seeberger

We show that effectively cold metastable states in one-dimensional photodoped Mott insulators described by the extended Hubbard model exhibit spin, charge, and q-spin separation. Their wave functions in the large on-site Coulomb interaction limit can be ex ...

AMER PHYSICAL SOC2023

Atomic-scale Characterization of Strain and Gate effects on Two-dimensional Materials by Scanning Tunneling Microscopy

Jz -Yuan Juo

Strain is an inevitable phenomenon in two-dimensional (2D) material, regardless of whether the film is suspended or supported. Moreover, strain is known to alter the physical and chemical properties, such as the band gap, charge carrier effective masses, d ...

EPFL2023

Machine-learning the electronic density of states: electronic properties without quantum mechanics

Chiheb Ben Mahmoud

The electronic density of states (DOS) quantifies the distribution of the energy levels that can be occupied by electrons in a quasiparticle picture and is central to modern electronic structure theory. It also underpins the computation and interpretation ...

EPFL2023

Investigation of thermoelectric nanomaterials

David Thomas Osenberg

Thermoelectric conversion remains an active research field in light of its potential to enhance energy efficiency by waste heat recovery in a noise and wear-free manner. Nanostructuring is responsible for most of the recently reported improvements of the ...

EPFL2023

Impact of rapid thermal processing on bulk and surface recombination mechanisms in FZ silicon with fired passivating contacts

Christophe Ballif, Franz-Josef Haug, Andrea Ingenito, Audrey Marie Isabelle Morisset, Sofia Libraro, Mario Joe Lehmann

We investigate bulk and interface recombination in crystalline silicon with p-type fired passivating contacts. These consist of a chemical oxide and an in-situ doped layer of SiCx with low carbon content. Following a rapid thermal annealing to activate the ...

ELSEVIER2022

One-Shot Approach for Enforcing Piecewise Linearity on Hybrid Functionals: Application to Band Gap Predictions

Alfredo Pasquarello, Stefano Falletta, Jing Yang

We present an efficient procedure for constructing nonempirical hybrid functionals to accurately predict band gaps of extended systems. We determine mixing parameters by enforcing the generalized Koopmans’ condition on localized electron states, which are ...

2022

Phase transition of layer-stacked borophene under pressure

Oleg Yazyev, Quansheng Wu, Xiao Dong

The 8-Pmmn borophene, a boron analog of graphene, hosts tilted and anisotropic massless Dirac fermion quasiparticles owing to the presence of a distorted graphenelike sublattice. First-principles calculations show that stacked 8-Pmmn borophene is transform ...

AMER PHYSICAL SOC2022

Metal-wire-embedded alumina insulating material using micro- and nanoscale 3D printing for surface flashover mitigation in a vacuum

Guang-Yu Sun

A micro- and nanoscale 3D printing technique is applied to fabricate a functional insulating material that mitigates surface discharge in a vacuum based on microscopic electron multipactor suppression. The proposed alumina ceramic insulator design consists ...

2022

Spectral properties of extended systems from Koopmans-compliant functionals

Riccardo De Gennaro

Electronic-structure simulations have been impacting the study of materials properties thanks to the simplicity of density-functional theory, a method that gives access to the ground state of the system. Although very important, ground-state properties rep ...

EPFL2022