Shaking up fermions into higher Bloch bands

20 May 2021

Photo: AG Hemmerich

For the first time, a fermionic quantum gas of neutral atoms is loaded to selected higher Bloch bands of an optical lattice. Extreme band lifetimes demonstrate the exquisite robustness of the system. Momentum spectra confirm the orbital character of the lattice. A novel regime of fermionic orbital optical lattices is opened, which should prove useful as an advanced generation of quantum simulators for electronic matter beyond s-band physics. The techniques 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 (BEC-BCS crossover). Hence, our work sets the stage for new fundamental insights into fermionic superfluidity in presence of orbital degrees of freedom.

Quantum degenerate Fermi gas in an orbital optical lattice
M. Hachmann, Y. Kiefer, J. Riebesehl, R. Eichberger, A. Hemmerich
Phys. Rev. Lett. 127, 033201 (2021), Highlighted as Editors' Suggestion
arXiv:2106.12241