Excitation Spectrum and Superfluid Gap of an Ultracold Fermi Gas

Probing the physics behind superconductivity

30 September 2022

Spectroscopic measurements on an ultracold atomic gas could provide new clues into superconductivity.

Systems of quantum particles that strongly interact with each other occur widely in nature, including in neutron stars and unconventional superconductors. But their complexity makes them extremely difficult to analyse.

Ultracold gases of atoms provide a convenient way to experimentally probe the physics of such strongly interacting systems. However, many regions in their spectra remain unexplored.

Now, a team led by researchers from the University of Hamburg in Germany has filled in one of those gaps by observing the spectrum of an ultracold gas of lithium atoms in the low-energy region.

They gleaned important insights into how the system switches from being a Bose–Einstein condensate — a state of matter where the system acts like a single atom — to a superfluid as the interaction between the atoms was ramped up.

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References

1. Physical Review Letters 128, 100401 (2022). doi: 10.1103/PhysRevLett.128.100401