SPM-TH

Scanning Probe Microscopy Theory & Nanomechanics Group
Forces and Transport in Nanostructures

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About us

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Our work is focused on ab initio modelling of different problems in Materials Science and Nanotechnology that involve forces and currents at the atomic scale. In particular, we try to understand and develop new capacities for the basic tools in Nanotechnology, the Scanning Probe Microscopes (SPMs), that enable us to use currents and forces to visualize and manipulate matter at the nanoscale.

We work, in close collaboration with experimental groups worldwide, in topics such as:

1. Scanning Tunneling (STM) and Atomic Force (AFM) Microscopes: Atomic contrast, energy dissipation mechanisms and nanomanipulation.
2. Nanomechanics: Fracture. Friction and Wear at the atomic scale. Mechanical and Transport properties of nanocontacts.
3. Adsorption, reactivity, and self-organization of fullerenes and other organic molecules on surfaces.
4. Reducible oxides for catalysis and energy harvesting applications.
5. Biomolecules: Multiscale studies of DNA and proteins in their native liquid environment.

We use a suite of total-energy methods based in Density Functional Theory (DFT) , --from very efficient codes based on local orbitals (OPENMX) to more accurate implementations with a plane-wave basis (VASP)-- in order to provide a realistic description of the mechanical and electronic properties. Transport properties are calculated with a non-equilibrium Green's function formalism, that can be naturally linked with the local orbital DFT methods.

For the biomolecular studies, we have devekoped a methodology based on steered molecular dynamics sumulations with AMBER classical force fields to characterize the adsorption and mechanical properties of large biomolecules.

Recent Research Highlights (2019)


Remy Pawlak, J.G. Vilhena, Antoine Hinaut, Tobias Meier, Thilo Glatzel, Alexis Baratoff, Enrico Gnecco, Rubén Pérez, and Ernst Meyer
Conformation and cryo-force spectroscopy to probe intra-molecular elastic properties of single-strand DNA on gold
Nature Communications 10, 685 (2019).    (DOI link)    (pdf)    (supp. info)

Alberto Marín-González, J. G. Vilhena, Fernando Moreno-Herrero and Rubén Pérez:
DNA crookedness: a structural code imprinted in the genome for regulating DNA mechanical properties at short length scales
Phys. Rev. Lett. 122, 048102 (2019).    (DOI link)    (pdf)    (supp. info) Read more...
   Research Highlight in Nature Reviews Physics

Michael Ellner, Pablo Pou, and Rubén Pérez
Molecular identifcation, bond order discrimination and apparent intermolecular features in atomic force microscopy studied with a charge density based method
ACS Nano 13, 786--795 (2019).    (DOI link)    (pdf)    (supp. info) Read more...