Pauli blocking enhanced life-times and cooperative radiation in a 2D Fermi gas*

The observation of  Pauli blocking of atomic spontaneous decay via direct measurements of the atomic population requires the use of long-lived atomic gases where quantum statistics,  atom recoil  and cooperative  radiative processes are all relevant.  We develop a theoretical framework capable of simultaneously accounting for these effects and apply it to atoms featuring an effective  $\Lambda$ level  structure confined in a single 2D pancake or arrays of pancakes.  We identify a parameter window in which a factor of two extension in the atomic lifetime clearly attributable to Pauli blocking  should be experimentally observable in deeply degenerate gases with  $\sim  10^{3} $ atoms. Consistent with these theory predictions, we experimentally observe  a $\sim$20\% suppressed excited state decay rate in the moderately degenerate regime on the  ${}^{1}\rm{S_0}-{}^{3}\rm{P_1}$ transition in $^{87}$Sr atoms.

Ref: arXiv:2108.02819