
cold atoms


Recent advances in experimental
control of old atomic systems allow one to realize strongly correlated
bosonic and fermionic states experimentally, establish novel phases of
matter, study topological excitations, or investigate prospects of
quantum computations.
One of the main
goals of our group is to identify and study theoretically exotic phases
appearing in cold atomic systems such as, e.g., the "baryonic"
state [Phys. Rev.
Lett. 98, 160405] or the color superfluid state emerging in
multicomponent fermionic systems, or novel quantum glass phases
appearing in BoseFermi mixtures [Phys. Rev.
Lett. 105, 115301]. We also study topological excitations in these
systems, such as, e.g., Skyrmions in strongly interacting
multicomponent systems, or vortices in nematic phases.
Our other main line of our research focuses on dynamical aspects of
cold atomic systems; we investigate nonequilibrium phenomena such as
out of equilibrium relaxation, postquantum quench dynamics [Phys. Rev.
Lett. 106, 156406] or work statistics.

nanosystems


Quantum interference effects and
correlation effects distinguish quantum transport through
nanostructures through quantum dots and nanowires from more
conventional transport.
We study
transport and dynamical correlations in correlated quantum systems
under out of equilibrium conditions using numerical and analytical
field theoretical methods such as functional or numerical
renormalization group techniques. We investigate, e.g. transport
through coupled double dot systems [Phys. Rev. Lett.
90, 026602], and sudy the emerging nonFermi liquid states
in these devices.
We also study the (quantum) noise spectrum of correlated quantum dots [Phys. Rev. Lett. 108, 046802 (2012)], and investigate the
dynamics of cavitycoupled quantum dots.

low
dimensional
systems


One of the most interesting effect
in 2D electron systems is the quantum Hall effect (QHE), a microscopic
quantum state of electrons in strong magnetic fields, that shows
topological order. The
integer QHE is a oneparticle effect, whereas the fractional QHE is a
manifestation of the strong correlation between electrons. The physics
of the lowest Landaulevel in the QuantumHall regime is well described
by the so called composite fermion model. However, on higher levels, or
in multilayer systems, the explanation of many effects is an open
question.
We investigate the
fractional QHE states on higher Landaulevels, particularly the
formation of nonAbelian states. We are also interested in anisotropic,
multicomponent and spinorbit coupled systems, and the QHE in
graphene and other recently discovered materials.


