Research Projects
The research in our group is divided into three main topics:

Computer Simulations

Density Functional Theory

CoarseGraining (via projectionoperator techniques).
Computer Simulations 

We use Monte Carlo (MC) simulation methods in order to study the materials properties of soft matter. Typical examples are liquid crystals and colloids. Fig.1 shows a simulation snapshot of a membrane of chiral rodlike particles. Liquid crystals consisting of chiral mesogenes show a rich phase diagram, including the usual isotropic, nematic and smectic phases, and the special cholesteric (or chiral nematic) phase, where the nematic director rotates continuously around an axis. In particular, biological materials exhibit such cholesteric phases, e.g. fd viruses and cellulose nanocrystals.
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(Fig.1: Twisted membrane of chiral rodlike particles) 
Density Functional Theory (DFT) 

We use classical density functional theory (DFT) to study structural properties of manybody systems. We mainly focus on mixtures of (charged) hard spheres and rods, which represent an important reference for more complex particles. Currently, we examine ionic structure in electric double layers (EDL) and connectivity in percolating networks. Our findings can be applied to study and optimize supercapacitors and related technology for harvesting energy from differences in concentration and temperature. The sketch in Fig.2 shows (from right to left) a supercapacitor, its porous electrode, and the EDL. Ref.: A. Härtel. J. Phys.: Condens. Matter 29, 423002 (2017)
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(Fig.2: (from right to left) a supercapacitor, its porous electrode, and the EDL) 
CoarseGraining 

In Statistical Physics problems, one is often interested in reducing the complexity of a manybody system by studying only a set of relevant observables. Such reductions in general go under the umbrella of coarsegraining, specially as soon as the natural timescale under which the observables of interest change is much larger than the microscopic timescale of the system. Within this framework, various projects are being conducted in the group aimed at developing coarsegraining techniques and formalisms that can also be applied in computer simulations, particularly under general outofequilibrium conditions. We mainly use projection operator techniques to derive stochastic equations of motion for coarsegrained observables. Such tools are specially useful to analyze memory effects occurring in many nonlinear systems.
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(Fig.3: A typical day at the office attempting to develop a coarsegrained theory) 