2D Materials

2D Materials

September 2017 – Scanning tunneling microscopy of in-situ exfoliated VSe2 reveals a non monotonic thickness dependence of the charge density wave (CDW) order parameter and phase transition temperature. Both parameters are extracted directly form the charge modulation amplitude imaged in STM micrographs. This study lifts the contradictions of previous experiments claiming opposite thickness dependencies of…

Physical Review B

Physical Review B

August 2017 – Reduced dimensions can give rise to surprising effects. While a long exposure time photograph of a macroscopic moving object appears blurred, scanning tunneling microscopy images of flipping Si dimer defects embedded in Bi-nanolines on the Si(001) surface appear much sharper than those of static ones. This counter intuitive dynamic sharpening is perfectly…

Physical Review Letters

Physical Review Letters

January 2017 – Combining scanning tunneling microscopy (STM) and density functional theory, we unambiguously identify Cu intercalated on the octahedral site in the van der Waals gap of 1T-CuxTiSe2. STM imaging shows that at low Cu content (x5%) it forms short-range ordered domains which tend to be phase shifted. Tunneling spectroscopy shows a well developed…

Nature Communications

Nature Communications

March 2016 – Scanning tunnelling spectroscopy on very homogeneous Y123 at 0.4K lift the veil on the vortex core spectroscopy. We find that the subgap features which have been challenging theoretical modelling for over twenty years do in fact not belong to vortices: they are observed everywhere along the surface with high spatial and energy…

Physical Review Letters

Physical Review Letters

December 2015 – Combining scanning tunneling microscopy, atomic force microscopy, and density functional theory we find that a simple necklacelike chain of single Mn atoms reproduces all the prominent features of Mn atom chains on Si(001), including their asymmetric appearance in filled states images not captured by current models. The upshot is a remarkably simpler…

Physical Review B Rapid

Physical Review B Rapid

August 2015 – The charge density wave (CDW) in 1T-TiSe2 is imaged by scanning tunneling microscopy in the presence of single atom defects.

Physical Review Letters

Physical Review Letters

May 2014 – The structural and doping nature of native atomic defects in TiSe2 are identified and characterized using scanning tunneling microscopy or spectroscopy and ab initio calculations. The dominant single atom dopants we identify are intercalated Ti atoms, Se vacancies, and Se substitutions by residual iodine and oxygen. Collaboration with UniFR and UCL/LCN. Phys….

Physical Review B

Physical Review B

July 2013 – In this study, we find that isolated heavy dopants behave entirely different at the surface compared to the bulk and to lighter dopants. The common light impurity P replaces individual Si atoms and maintains the integrity of the dimer superstructure of the Si(001) surface, but loses its valence electrons to surface states….

ACS Nano

ACS Nano

April 2013 – Hydrogen dangling bonds are highly reactive and their selective exposure on hydrogenated Si(001) using scanning probes is developing as a powerful lithography to pattern molecules and atoms. We have found that hydrogen is more weakly bound along the centre of Haiku stripes, thus offering a new, fully scalable thermodynamic route to produce…

PRL – Editor’s suggestion

PRL – Editor’s suggestion

June 2012 – Measuring the piezoresistance in p-type silicon up to 3GPa, we found it to decrease with compressive stress beyond the predicted saturation. This result has potential implications for the Si technology roadmap. Collaboration with Ecole Polytechnique Palaiseau and IEMN. Article featured in EE Times News&Analysis. Phys. Rev. Lett. 108, 256801 (2012)

Réalisation : Sur Mesure concept