Quantum Systems Unit (Thomas Busch)
Ultracold quantum gases have over the past two decades become one of the go-to systems for studying quantum mechanics in clean and highly configurable settings. A large number of techniques exist that allow to change almost any part of the Hamiltonian over a broad range of parameters and thereby create fully controllable synthetic quantum systems that can be used to explore physics in new regimes and with low noise. They are also paradigmatic systems to explore ideas and concepts from quantum information and quantum engineering.
Our theoretical work focuses on different aspects of these systems, and we are particularly interested in understanding the influence of interactions on the dynamics and control of few particle systems. This includes mean-field dynamics in superfluid condensates, but also the exact dynamics in multi-component, small and/or low-dimensional quantum systems. In particular we concentrate on studying adiabatic dynamics, STA dynamics and quench dynamics starting from well-defined initial states. The influence of correlations on many-body physics is one of our focal points and, more recently, the characterisation of systems via ideas from quantum thermodynamics.
At the same time, we also carry out work on light-matter interactions for atoms trapped in the nearfield of an optical nanofiber. We are moving the description of such systems towards more complicated settings, opening the possibilities for more control and new physical effects. This work, as most other works as well, is close to experimentally realistic setups, which is an important aspect of all projects carried out.
A quantum engine in the BEC–BCS crossover
Jennifer Koch, Keerthy Menon, Eloisa Cuestas, Sian Barbosa, Eric Lutz, Thomás Fogarty, Thomas Busch & Artur Widera Nature volume 621, pages 723–727 (2023)
Check out our press release from here.
The first time in three years the CQD was a great success. Everyone seemed to be engaged in lively and deepening discussions.