Freiburg 2024 – scientific programme
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A: Fachverband Atomphysik
A 3: Bosonic Quantum Gases I (joint session Q/A)
A 3.6: Talk
Monday, March 11, 2024, 12:15–12:30, Aula
Ramsauer Townsend effect and Bragg scattering in an analogue cosmology experiment — •Marius Sparn1, Elinor Kath1, Nikolas Liebster1, Christian F. Schmidt2, Álvaro Parra-López3, Mireia Tolosa-Simeón4, Helmut Strobel1, Stefan Floerchinger2, and Markus K. Oberthaler1 — 1Kirchhoff-Institut für Physik, Universität Heidelberg — 2Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena — 3Departamento de Física Teórica and IPARCOS, Universidad Complutense de Madrid — 4Institut für Theoretische Physik III, Ruhr-Universität Bochum
Cosmological particle production arises when a quantum field is subject to an expanding metric. This phenomenon heavily depends on the details of the cosmological history. Strikingly, this relativistic, time-dependent process can be mapped to a scattering problem, described by a non-relativistic stationary Schroedinger-equation, wherein the scattering potential is determined by the specific form of the expansion. Here we present results from an analogue cosmology experiment with a two-dimensional Bose-Einstein condensate, simulating a scalar quantum field in a FLRW-spacetime [1]. We use the scattering framework to investigate instructive examples, such as a box potential, corresponding to a singular expanding space-time as well as a periodic potential, corresponding to a periodic expansion and contraction. The measured spectra of produced particles reveal features analogue to resonant forward (Ramsauer-Townsend) scattering and Bragg scattering, respectively. [1] Viermann, C. et al. Nature 611, 260-264 (2022)
Keywords: Analogue Gravity; Bose-Einstein Condensates; Quantum Simulation; Ultracold Atoms; Cosmology