Physics of impurities in a Bose gas

• Applicant: Professor Dr. Hans-Werner Hammer, since 10/2019
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Theoretical Condensed Matter Physics
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413495248

This project addresses static and dynamic properties of quantum impurities in cold ose gases. A convenient way to study such systems is to use the notion of the polaron – a quasiparticle that is often pictured as an impurity dressed with low-energy excitations (phonons)of an environment.The polaron problem is central to our understanding of certain semiconductors, high-temperature superconductors and many other materials. Its importance is well understood but its solution is still out of reach of current classical computers. Very recently, following the idea of analog quantum computation, these quasiparticles were created in cold bosonic gases. This experimental achievement provided a platform for testing various theoretical models and conceptual ideas; it deepens our understanding of paradigmatic condensed matter systems with impurities, and places the Bose polaron problem at the forefront of the physics of quantum gases.The main objective of this proposal is to expand our understanding of the physics of impurities in cold-atom experiments. In particular, I would like to investigate the time dynamics of impurities in one-dimensional harmonically-trapped Bose gases, emergent impurity-impurityinteractions, and the possibility to measure properties of the environment using the impurity as a probe.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Artem Volosniev, until 10/2019