Ruprecht Karls Universit├Ąt Heidelberg

Superfluidity and long-range coherence in a 2D Fermi gas

In our recent experiments, we observed the Berezinskii-Kosterlitz-Thouless (BKT) phase transition in a 2D Fermi gas. We have measured, for the first time, the non-local correlations of a many-body system. We saw the onset of power-law behavior at low temperatures. More interestingly, we measured the scaling exponents and observed that the inhomogeneity of the system leads to a change of the universal critical exponents predicted by the BKT Theory.

The results of this work have been recently published in Physical Review Letters 115, 010401 (2015) (also available at arXiv:1505.02123). The paper was also selected for an Editors' Suggestion!

EDV Abteilung