It is hard to imagine that the most strongly interacting nonrelativistic system known is a quantum degenerate atomic Fermi gas comprising just a few hundred thousand spin-up and spin-down atoms in an optical trap. An external magnetic field controls the strength of the scattering between spin-up and spin-down atoms, which interact very strongly when the field is correctly tuned. Evaporative cooling in the optical trap efficiently brings the temperature down to the quantum degenerate regime, where the atomic momentum is so small that the de Broglie wavelength is comparable to the interatomic spacing and quantum statistics is important. Quantum degenerate, strongly interacting Fermi gases, first produced 1 in 2002, are now widely studied. 2 They provide model systems for tabletop studies of high-temperature superconductivity, neutron stars, and nuclear matter.
Remarkably, those supercold Fermi gases share a feature with an exotic soup of quarks and gluons, a quark-gluon plasma (QGP), that...
