Quantum Degenerate Fermi Gas in an Orbital Optical Lattice

Spin-polarized samples and spin mixtures of quantum degenerate fermionic atoms are prepared in selected excited Bloch bands of an optical checkerboard square lattice. For the spin-polarized case, extreme band lifetimes above 10 s are observed, reflecting the suppression of collisions by Pauli's exclusion principle. For spin mixtures, lifetimes are reduced by an order of magnitude by two-body collisions between different spin components, but still remarkably large values of about 1 s are found. By analyzing momentum spectra, we can directly observe the orbital character of the optical lattice. The observations demonstrated here form the basis for exploring the physics of Fermi gases with two paired spin components in orbital optical lattices, including the regime of unitarity.

Automated summary

In this study, spin-polarized samples and spin mixtures of quantum degenerate fermionic atoms are prepared in selected excited Bloch bands of an optical checkerboard square lattice. The extreme band lifetimes above 10 s for the spin-polarized case reflect the suppression of collisions by Pauli's exclusion principle. The remarkable large values of about 1 s found for spin mixtures demonstrate the basis for exploring the physics of Fermi gases with two paired spin components in orbital optical lattices, including the regime of unitarity.