Related Experiment Video
Updated: May 14, 2026
13:58
Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics
Published on: September 28, 2016
What about U on surfaces? Extended Hubbard models for adatom systems from first principles.
Philipp Hansmann1, Loïg Vaugier, Hong Jiang
1Centre de Physique Théorique, Ecole Polytechnique, CNRS-UMR7644, 91128 Palaiseau, France. philipp.hansmann@cpht.polytechnique.fr
Journal of Physics. Condensed Matter : an Institute of Physics Journal
|February 13, 2013
Summary
Electronic correlations in semiconductor surfaces are crucial for novel physics. This study quantifies these interactions for group IV adatoms on Si(111), revealing large Coulomb interactions and enabling new many-body calculations.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Semiconductor (111) surfaces and adatom systems exhibit fascinating properties due to electronic correlations and dimensional constraints.
- Many-body theoretical studies on these systems, beyond the standard band picture, are scarce.
- First-principles calculations of inter-electronic Coulomb interactions are often missing, with these parameters typically treated as adjustable.
Purpose of the Study:
- To calculate the interaction parameters for group IV surface-adatom systems on Si(111).
- To investigate the significance of inter-electronic Coulomb interactions and intersite interactions in these systems.
- To construct an extended Hubbard model for further many-body investigations.
Main Methods:
- First-principles electronic structure calculations.
- Estimation of inter-electronic Coulomb interaction parameters.
- Development of an extended Hubbard model.
Main Results:
- Calculated large inter-electronic Coulomb interactions for Si(111):C, Si, Sn, Pb systems, significantly exceeding kinetic energies.
- Demonstrated the non-negligible contribution of intersite interactions.
- Successfully constructed an extended Hubbard model applicable to the studied series.
Conclusions:
- The calculated interaction parameters are essential for accurate theoretical descriptions of these correlated systems.
- The developed extended Hubbard model provides a foundation for advanced many-body studies.
- This work bridges a critical gap in theoretical understanding of correlated electron behavior on semiconductor surfaces.
More Related Videos
Related Concept Videos
02:00Molecular Models
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
01:29Adsorption Isotherms I
Adsorption isotherms are mathematical models that describe how molecules in a gas or liquid phase interact with surfaces. Two of the most common isotherm models are the Langmuir and Freundlich isotherms, which relate to Type I monolayer chemisorption. The Langmuir model is based on four key assumptions:• Adsorption cannot exceed monolayer coverage.• All surface sites are equivalent.• Molecules adsorb only at vacant sites.• There are no interactions between adsorbed molecules.Consider the...
02:06Newman Projections
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
02:38Valence Bond Theory and Hybridized Orbitals
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
01:10Van der Waals Equation
The ideal gas law is an approximation that works well at high temperatures and low pressures. The van der Waals equation of state (named after the Dutch physicist Johannes van der Waals, 1837−1923) improves it by considering two factors.
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
02:45The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...