Transition from a polaronic condensate to a degenerate Fermi gas of heteronuclear molecules

Understand

The interplay of quantum statistics and interactions in atomic Bose--Fermi mixtures leads to a phase diagram markedly different from pure fermionic or bosonic systems.

• However, investigating this phase diagram remains challenging when bosons condense.
• Here, we observe evidence for a quantum phase transition from a polaronic to a molecular phase in a density-matched degenerate Bose--Fermi mixture.
• The condensate fraction, representing the order parameter of the transition, is depleted by interactions and the build-up of strong correlations results in the emergence of a molecular Fermi gas.