Towards quantum simulations of chemical and biological processes using ultra-cold Rydberg atoms

Ultracold Rydberg atoms constituting a ``frozen gas'' have become a
versatile tool well beyond atomic physics and serve as experimentally
accessible interacting many-body systems for quantum information and
in condensed matter physics.  While for those applications the
residual atomic motion is usually an unavoidable perturbation and
source of noise, we will use this motion for preserving coherent
electronic transport, very much like in molecules.

During acceleration of several Rydberg atoms due to resonant
dipole-dipole interactions, the responsible Born-Oppenheimer surfaces
of the atomic system provide an intricate link between atomic motion
and excitation transport.  This link allows the engineering of
adiabatic exciton transport schemes, laboratory accessible conical
intersections or mesoscopic entangled atom clouds. These conical
intersections among dipole Born-Oppenheimer surfaces allow the
detailed monitoring of many-body dynamics near the intersection and
can further be functionalised as switches for exciton transport.

On shorter time scales where motion is no longer crucial, the system
shows parallels to energy transport in light harvesting
complexes. Consequently Rydberg atoms can provide a clean analog
system for the quantum simulation of photosynthetic energy transport,
into which crucial complex features like disorder and decoherence can
be introduced in a controlled manner.  This control can be achieved by
embedding the assembly of Rydberg atoms into a background atomic gas.

After a brief overview of the concept of quantum simulation and
analogies to ultra cold atom systems recently exploited by a number of
disciplines, I will focus on the above studies related to chemical
problems and the prospects to describe biological processes.