Mainz 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

A: Fachverband Atomphysik

A 27: Ultra-cold Atoms, Ions and BEC III (joint session A/Q)

A 27.1: Invited Talk

Thursday, March 5, 2026, 11:00–11:30, N 1

Quantum-enabled active matter at the atomic scale — •Sabrina Burgardt¹, Julian Feß¹, Silvia Hiebel¹, Alexander Guthmann¹, Aritra K. Mukhopadhyay², Sangyun Lee³, Michael te Vrugt³, Benno Liebchen², Hartmut Löwen⁴, Raphael Wittkowski^5,6, and Artur Widera¹ — ¹Department of Physics and State Research Center OPTIMAS, RPTU University Kaiserslautern-Landau, Erwin-Schrödinger-Str. 46, 67663 Kaiserslautern, Germany — ²Institute for Condensed Matter Physics, Technical University of Darmstadt, Hochschulstraße 8, 64285 Darmstadt, Germany — ³Institute of Physics, Johannes-Gutenberg University Mainz, Staudingerweg 9, 55128 Mainz, Germany — ⁴Institute of Theoretical Physics II: Soft Matter, Heinrich-Heine University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany — ⁵Department of Physics, RWTH Aachen University, Forckenbeckstr. 50, 52074 Aachen, Germany — ⁶DWI – Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074 Aachen, Germany

Active particles, which are able to extract energy from their local environment and convert it into motion, have been widely studied in robotics, biology, and soft matter science. So far, it is unclear whether activity can be realized on the much smaller scale of individual quantum systems. Here, we experimentally demonstrate that optically trapped ¹³³Cs atoms are able to extract energy via nonreciprocal quantum-mechanical spin-exchange interactions from a thermal cloud of ⁸⁷Rb atoms and convert this energy into active motion. It is found that the quantum-enabled activity has significant effects on the in-trap dynamics. We quantitatively reproduce the experimental findings with numerical Monte-Carlo collision simulations and with an active Langevin model for the motion of the ¹³³Cs atoms. Our results open the door to combining effects of quantum mechanics and activity, allowing to design novel exotic far-from-equilibrium systems.

Keywords: Active Particles; Single Impurities