Quantum Microscope Images Fermionic Atoms
Fluorescence image of atoms in a single layer of a cubic lattice obtained using Raman sideband cooling. The filling fraction in the center of the cloud is 40%. Approximately 750 photons per atom are collected during a 1.9 s exposure. The color bar is in arbitrary units*. [Copyright 2015 by the American Physical Society]
In a new article* in Physical Reviews Letters, also featured in Physics, Prof. Markus Greiner and members of his lab described a new technique for imaging of individual fermionic lithium atoms in a single layer of a 3D optical lattice. To preserve the density distribution during fluorescence imaging, the researchers simultaneously cooled the atoms with 3D Raman sideband cooling. They were able to determine the occupation of individual lattice sites with a fidelity >95%, enabling direct, local measurement of particle correlations in Fermi lattice systems. This ability will be instrumental for creating and investigating low-temperature phases of the Fermi-Hubbard model, including antiferromagnets and d-wave superfluidity.
*See M.F. Parsons, F. Huber, A. Mazurenko, C.S. Chiu, W. Setiawan, K. Wooley-Brown, S. Blatt, and M. Greiner, "Site-Resolved Imaging of Fermionic 6Li in an Optical Lattice," Phys. Rev. Lett. 114, 213002 | DOI: http://dx.doi.org/10.1103/PhysRevLett.114.213002.