*ITAMP Lunch Seminar* *Speaker: *Daniel Greif (Harvard University) *Date:* Thursday, April 26th *Time:* 12:00-1:00 pm Includes Pizza. *Title: *New Frontiers in Fermionic Quantum Gas Microscopy *Abstract: Quantum gas microscopy of ultracold fermionic atoms in optical lattices allows studying strongly correlated low-temperature phases in the Hubbard model. Through an entropy redistribution technique we have demonstrated long-range antiferromagnetic order extending over our entire sample, a disk spanning ten sites across filled with a two-component spin mixture of ultracold fermionic Li-6 atoms in a square lattice. Our microscope provides access to quantities such as the site-resolved spin correlation function, spin structure factor, and full counting statistics of the staggered magnetization. By hole doping the system away from half-filling we explore regimes of the Hubbard model phase diagram where precise numerical studies become challenging. We study the interplay between hole motion and the antiferromagnetic order: when a hole tunnels in an antiferromagnet, it can distort the surrounding order and form a string. This could be an essential aspect of high-temperature superconductivity in cuprates, and the readout of our microscope allows us to directly address this question. Besides discussing our current progress in this direction, I will also explain a new cooling technique based on quantum engineering of ultra-low entropy band-insulators to obtain even lower temperature states.* *Location: *B-106 @ Center for Astrophysics (60 Garden Street) *Directions: *After entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, B-106 will be at the end of the hallway on the left side.