Publications related to Crossing the ballistic-ohmic transition via high energy electron irradiation

Catalyzing Bond-Dissociation in Graphene via Alkali-Iodide Molecules

Klaus Kern, Stephan Rauschenbach, Sabine Abb, Sven Alexander Szilagyi, Hannah Julia Ochner

Atomic design of a 2D-material such as graphene can be substantially influenced by etching, deliberately induced in a transmission electron microscope. It is achieved primarily by overcoming the threshold energy for defect formation by controlling the kine ...

WILEY-V C H VERLAG GMBH2021

Atomic-scale insights into the origin of rectangular lattice in nanographene probed by scanning tunneling microscopy

Shaoxian Li

We conducted atomic-scale scanning tunneling microscopy of a graphene nanosheet on graphite. In addition to a rhombus lattice representing the (root 3x root 3)R30 degrees superstructure, we resolved another quadrangle lattice similar to a rectangle in the ...

AMER PHYSICAL SOC2021

Edge Disorder in Bottom-Up Zigzag Graphene Nanoribbons: Implications for Magnetism and Quantum Electronic Transport

Oleg Yazyev, Michele Pizzochero, Kristians Cernevics

We unveil the nature of the structural disorder in bottom-up zigzag graphene nanoribbons along with its effect on the magnetism and electronic transport on the basis of scanning probe microscopies and first-principles calculations. We find that edge-missin ...

AMER CHEMICAL SOC2021

Systematic design of millisecond gasification reactor for the incorporation of gas-sieving nanopores in single-layer graphene

Kumar Varoon Agrawal, Kuang-Jung Hsu, Luis Francisco Villalobos Vazquez de la Parra, Shiqi Huang, Shaoxian Li

Etching an ensemble of vacancy defects (nanopores) in single-layer graphene (SLG) to obtain a high density of nanopores with an effective size that enables high-performance gas sieving is challenging. This is because nanopore nucleation and expansion are u ...

2021

Electrons leave the flatland: out-of-plane charge dynamics in layered materials

Edoardo Martino

The goal of this thesis is to explore the "neglected" third dimension of layered materials, by studying the interlayer charge dynamics through dc conductivity, optical spectroscopy and ab-initio calculations. This project was designed to respond to the gro ...

EPFL2020

Measuring the Intra-Atomic Exchange Energy in Rare-Earth Adatoms

Harald Brune, François Patthey, Stefano Rusponi, Marina Pivetta

We present the first experimental determination of the intra-atomic exchange energy between the inner 4f and the outer 6s5d shells in rare-earth elements. Inelastic electron tunneling spectroscopy on individual rare-earth atoms adsorbed on metal-supported ...

American Physical Society2020

Electronic, excitonic and magnetic properties of two-dimensional heterostructures

Alberto Ciarrocchi

Two-dimensional (2D) crystals such as graphene or transition metal dichalcogenides (TMDCs) are a fascinating class of quantum materials. These compounds are obtained isolating the single atomic sheets that normally form bulk layered crystals, and the reduc ...

EPFL2020

Even-odd conductance effect in graphene nanoribbons induced by edge functionalization with aromatic molecules: basis for novel chemosensors

Oleg Yazyev, Michele Pizzochero, Kristians Cernevics

We theoretically investigate the electron transport in armchair and zigzag graphene nanoribbons (GNRs) chemically functionalized withp-polyphenyl and polyacene groups of increasing length. Our nearest-neighbor tight-binding calculations indicate that, depe ...

2020

Charge transport in proximitized graphene within van der Waals heterostructures

Katharina Polyudov

Since their discovery, graphene and other 2D materials have become a subject of intense research in condensed matter physics. Especially the vast possibilities of combining those materials into heterostructures are promising for the discovery of novel phys ...

EPFL2020

Super-geometric electron focusing on the hexagonal Fermi surface of PdCoO2

Philip Johannes Walter Moll, Maja Deborah Bachmann, Matthias Carsten Putzke

Geometric electron optics may be implemented in solids when electron transport is ballistic on the length scale of a device. Currently, this is realized mainly in 2D materials characterized by circular Fermi surfaces. Here we demonstrate that the nearly pe ...

Nature Research2019