Ultracold allows the study of Ultrahot and Ultralarge

Date

Oct 21, 2024

Time

4:30 PM - 5:30 PM

Speaker

Prof. Dr. Markus Oberthaler

Affiliation

Heidelberg University

Series

MPI-PKS Kolloquium

Language

en

Main Topic

Physik

Other Topics

Physik

Description

The experimental platform of ultracold gases provides a unique opportunity to study a diverse range of phenomena in physics. In this presentation, I will provide an overview of how ultracold gases can be employed to investigate the physics in the quantum field theoretical limit. As the first example I will present the connection to quark-gluon plasma, a state of matter that emerges following the collision of heavy ions at CERN. This state of matter is known as the hottest state of matter produced on Earth and has a temperature of approximately 1012°K, which is about 20 orders of magnitude higher than that of ultracold gases i.e. ultrahot. Nevertheless, the far equilibrium situation in ultracold gases after a quench exhibits a temporal evolution that is analogous to that predicted for the state of matter directly following a heavy ion collision [1]. The key of these experiments lies in the utilisation of composite quantum fields, rather than the fundamental fields themselves. This approach presents novel avenues for investigating quantum field theoretical settings [2]. Platforms offering this possibility we classify as quantum field simulators. As a second example of exploring ultralarge, I will present our study of the expansion of spacetime in the limit of the cosmological principle, which assumes homogeneity and isotropy of the universe. Assuming this, the metric for large scales is given by the Friedmann-Lemaitre-Robertson-Walker metric, which is fully characterised by the sign of the curvature and a general scale factor, both are under full control in the experiments with ultracold gases. I will discuss how different curvatures can be realised as well as particle production in expanding spacetime can be detected [3]. These are just two examples of how the experimental platform of ultracold gases can be utilised to address fundamental questions; there are many more to come in the future. References [1] M. Prüfer, et al., Nature, 563, 217 (2018) [2] M. Prüfer, et al. Nature Physics, 16, 1012 (2020) [3] C. Viermann, et al. , Nature, 611, 260 (2022)

Last modified: Oct 21, 2024, 7:39:23 AM