Spontaneous emission in ultracold spin-polarized anisotropic Fermi seas
American Physical Society
We examine and explain the spatial emission patterns of ultracold excited fermions in highly anisotropic trapping potentials in the presence of a spin-polarized Fermi sea of ground-state atoms. Due to the Pauli principle, the Fermi sea modifies the available phase space for the recoiling atom. This leads to the well-known modification of the atomic decay rate, but also to a spatial modulation in the probability of the emitted photon's direction. In this work we carry out the first detailed investigation into these spatial anisotropies and show that they are due to an intricate interplay between Fermi energies and degeneracy values of specific energy levels. We identify different regimes and show that the emission can be engineered to become highly directional. As the latter is usually only possible in cavity settings, our results describe an alternative idea for a directional photon source.
Gas , Atoms
O’Sullivan, B. and Busch, T. (2009) 'Spontaneous emission in ultracold spin-polarized anisotropic Fermi seas', Physical Review A, 79(3), 033602 (7pp). doi: 10.1103/PhysRevA.79.033602
© 2009, American Physical Society