Collective Quantum Dynamics

Course with Participations of Group Members

Offers for Theses in the Group

Prethermalization in the Bose-Hubbard model

When an isolated quantum system is set in motion, what happens? In classical thermodynamics, this problem is exemplified by the irreversible expansion of a gas in an isolated chamber after suddenly doubling the chamber size. Generically, we expect to observe a gradual relaxation to a thermal equilibrium state as the details of the initial state are progressively washed away in collisions. In certain cases, however, strong quantum correlations between the particles can conspire to slow down the relaxation process, resulting in a multi-stage dissolution of the initial information via long detours to intermediate states. In technical terms, these intermediate states are referred to as prethermal states. In this project, we will study signatures of prethermalization in the Bose-Hubbard model using a truncated phase space method.

suitable as

• Master’s Thesis Condensed Matter Physics
• Master’s Thesis Nuclear, Particle, and Astrophysics

Supervisor: Michael Knap

Thermalization and relaxation of quantum systems

Recent conceptional and technical progress makes it possible to prepare and explore strongly-correlated non-equilibrium quantum states of matter. Such states can be very well controlled in synthetic quantum matter, such as ultracold atoms, trapped ions, or quantum dots. However, theoretically many facets of non-equilibrium states are not well understood. Among them are thermalization in closed quantum systems, dynamic phase transitions, and intertwined order far from equilibrium. In this project we will explore state of the art questions of the field of nonequilibrium quantum dynamics that are also of direct relevance to current experiments.

suitable as

• Bachelor’s Thesis Physics
• Master’s Thesis Condensed Matter Physics
• Master’s Thesis Nuclear, Particle, and Astrophysics

Supervisor: Michael Knap

Disordered quantum systems: Many-body localization

Disorder has a drastic influence on transport properties. In the presence of a random potential, a system of electrons can become insulating; a phenomenon known as many-body localization (MBL) that has been envisioned by the Nobel laureate Phil Anderson. However, even beyond the vanishing transport such systems have very intriguing properties. For example, many-body localization describes an exotic state of matter, in which fundamental concepts of statistical mechanics break down. In this project we will explore these exciting aspects of many-body localization.

suitable as

• Bachelor’s Thesis Physics
• Master’s Thesis Condensed Matter Physics

Supervisor: Michael Knap

Current and Finished Theses in the Group