Research Topics

Physics

Hadron physics

At high energies experiments have found new and potentially exotic mesons, with properties at odds with quark models. We study these new states from first principles using lattice QCD, using direct approaches to establish the nature of these states, e.g. as hadronic molecules or pure tetraquarks. Furthermore, it is possible to supply the necessary low energy constants required for a chiral perturbation theory analysis of interesting states directly from lattice QCD simulations. Precision calculations in the sense of controlled systematic uncertainties (in particular the chiral limit and finite volume effects) are still missing for a large number of these quantities, but are within the reach of present systems using established methods. We aim to extend our spectroscopy calculations aiming for excited states in various channels in the future.
Precision calculations of nucleon properties are becoming increasingly feasible, driven both by algorithmic and hardware advances. From nucleon charges , e.g. relevant for beyond the Standard Model (BSM) physics, to transverse momentum-dependent parton distribution functions (TMDs) , we calculate observables at physical quark masses using suitable lattice discretizations, such as domain wall fermions where chiral mixings need to be controlled.

One of our long term goals is to understand how QCD computations can contribute to nuclear physics.

Strongly correlated electrons in low dimensions: carbon nanostructures

Carbon nanostructures are low dimensional systems with fascinating properties, such as physical strength, conductivity, and strongly correlated electronic behavior. The tremendous potential for industrial applications of carbon nanostructures ultimately drove the EC to select “Graphene” as one of its FET Flagship projects. Fortunately, these systems are amenable to the advanced simulation techniques developed for lattice QCD. More precisely, techniques developed for calculating pion and baryon systems in lattice QCD can be directly applied to measuring the quasi-particle excited states in these low-dimensional systems, such as excitons and trions. Using our simulation methods, we study the phase structure of graphene, the electronic structure of nanotubes and ribbons, as well as other low-dimensional strongly correlated systems. Such materials are candidates for next-generation electronics as well as topological quantum computers (QC).

Computational Science

Modular Supercomputer Architecture

The integrated supercomputer design called Modular Supercomputing Architecture (MSA) connects modules optimized for different workloads into one system through a high-performance interconnect. Optimally using these modules for the different parts and separate stages of the simulation setup requires a suitable simulation software. We develop methods and implementations to utilize the new possibilities of the MSA for numerical quantum field theory applications, with an ephasis of collaborative software development.

Exascale computing

We are involved with the exascale efforts at JSC with the aim to analyze future HPC architectures, with particular emphasis on their suitability quantum field theory simulations.