Our proposal for ac-driven quantum ratchets with
ultracold atoms (BEC) [23, 24] has been realized by the group of Martin Weitz [Science 326, 1241 (2009)]. They observed a whole spectrum of theoretically
predicted effects and thus demarcated their quantum ratchet from classical ones.
We have demonstrated, both theoretically (Augsburg) and experimentally (Bonn), that the mobility of a BEC in an ac-driven optical potential can be tuned by modifing the Floquet spectrum of the system.
Here you can see the results of some experiments on ac-driven quantum ratchets I have performed under the supervision of
Christopher Grossert in the Bonn lab (to be more precise, I was allowed to click the buttons).
The time-of-flight measurements reveal velocity distribution of a BEC cloud after the
exposition to an ac-driven optical lattice potential.
Open quantum systems and Dissipative Quantum Chaos
Dissipative Quantum Chaos is an emerging theory that addresses open quantum many-body systems;
its agenda is to quantify generic properties of the dissipative quantum evolution and
provide a toolbox to sort the systems into "chaotic" and "regular" ones. Another words, it is
an idea to generalize to open (dissipative) quantum systems the concept known as
Quantum Chaos Theory (which addresses unitary (Hamiltonian) quantum evolution).
It is hard to describe this topic in a few words, it is rather a vision [see the outline of a recently organized
workshops (2017, 2022)].
We have made some steps in [76,
We believe that Dissipative Quantum Chaos is a framework
which can be used to test and control the current generation of Noisy Intermediate-Scale Quantum (NOS) computers.
This is the core idea of the DQUANT project.
Computational Quantum Physics
Many-body Floquet states of strongly-driven systems: numerical methods and algorithms [56,
Open quantum systems: asymptotic nonequilibrium states ('quantum attractors') and relaxations
towards them [57, 61]
Energy exchange between quantum systems and relaxation to
equilibrium [33, 35, 39].
Lévy walks, complex transport and biodynamics
Lévy walks are a specific type of random walks which
found applications in diverse research corners ranging from quantum physics and chaotic dynamics to ecology, cellular biophysics and robotics.
Currently, we are trying to apply this concept to biological transport, transport phenomena in two- and three-dimensional spaces, and optimal search theory.
On these subjects I enjoy collaboration [36,
43, 46, 50,
with V. Zaburdaev (University of Erlangen-Nuremberg, Germany) and E. Barkai (Bar-Ilan University, Israel).
Teaching Quantum Computing to IT students
Quantum computing (QC) is no longer a mere academic subject but also one of the fastest growing IT
sectors. It is a perspective job market for IT specialists, and we are already
situation when the demand for experts both in IT and computer science (CS) and QC exceeds the
We think that the way QC is taught currently should be revised.
Our hypothesis is that IT/CS students can be led directly to the field of QC without prior knowledge of quantum mechanics.
Our course on Quantum Information Technology is a blend of
basics of Qauntum Mechanics, QC theory, and a practial coding, by using online cloud platoforms such as
IBM Quantum Experience and D-Wave's Leap. We also use our two- and three-qubit
quantum computers based on the NMR technology, Hugin and Munin (see Hugin on the left).