Research areas on Applied Physics

Atomic Modeling

We study the dynamics of spins, atoms, molecules and materials on different length and time scales. Spin is used to study magnetic properties and superconductivity while atoms are used to study different aspects of material dynamics. For many material dynamics simulations, it is sufficient to use atoms as the smallest building blocks, not electrons as we do in electron structure theory.

This model theory is usually called Molecular Dynamics (MD) - more specifically Molecular Mechanics based Molecular Dynamics (MM-MD). MD is used to study the dynamics of gases, liquids and solutions, and the solid state, and it includes effects from vibrational, electrostatic and dispersion type interactions. These interactions are defined by so-called "force fields", which are normally fitted to the system in question with properties from experimental measurements or density functional theory simulations. It is a theory that describes van der Waals interactions very accurately at a very reasonable computational cost, and can be used to model millions of atoms with a step-length on the femtosecond scale - resulting in dynamical information typically over several nanoseconds. MM-MD in its general form is not suitable for studying dynamic processes of bond breaking and formation, for which ab initio molecular dynamics is needed (ai-MD).

Electron structure teori

The group studies atoms, molecules, clusters and material properties by calculating their electronic structures. For this we apply the laws of quantum mechanics in the form of the Schrödinger equation through wave function methods and, above all, density functional theory (DFT). Our calculations are performed on high performance computers at the Swedish Supercomputer Center (HPC2N, NSC and PDC) using advanced computer programs.

Our research contributes to the improvement of these computational methods for faster simulations and enabling simulations of larger systems.

Our special expertise lies in calculations of dislocations and defects in materials, metal-molecule and metal-semiconductor interactions, chemical bonding and weak dispersion-driven bonds (van der Waals interactions), as well as theoretical scanning tunneling microscopy (STM) images and curves.

Atomic, molecular and astrophysics

Our group's research is in theoretical atomic, molecular and optical physics. Especially molecular collisions in the gas phase, in combination with reactive processes and interactions with electromagnetic radiation. The applications of the research are typically in astro-environments, such as the interstellar medium and planetary atmospheres.

Fundamental theoretical physics

Research is conducted in theoretical physics, with emphasis on the most fundamental and conceptual level such as particle physics, relativity/gravity, cosmology and quantum physics.

• Preons & Preon stars
• Cosmic Neutromagnets
  
• Masses of elementary particles
• Cosmology without acceleration
• The measurement problem of quantum physics