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A Quantum Gas Microscope for Detecting Single Atoms in a Hubbard-Regime Optical Lattice Hyuneil Kim, Zhidong Leong, Yulia Maximenko, Jason Merritt (University of Illinois at Urbana-Champaign) Goals and Motivation •To build a quantum gas microscope with fidelity high enough for detecting every single atom in a Hubbard-regime optical lattice. •To bridge the current macroscopic and microscopic approaches for studying quantum systems in the Hubbard regime, relating thermodynamic ensembles to small quantum systems. What is a Hubbard-Regime Optical Lattice? ● Lattice sites end up empty or singly occupied When the optical lattice is first applied, sites may contain multiple atoms, but over a short timescale (~100µs) pairs of atoms occupying the same site undergo light-assisted collisions and are ejected from the system. Result: -Sites with even numbers of atoms end up empty as atoms pair off -Sites with odd numbers of atoms end up with one atom Individual lattice sites were successfully detected with very high stability and fidelity Single atoms on a 640-nm-period optical lattice An optical lattice is a periodic potential formed by interfering laser beams. -Ultracold atoms in the lattice can tunnel and interact with each other, forming various phases, such as superconductivity, superfluidity, and Mott insulator. In the Hubbard regime, there is a strong electron-electron interaction, which is characteristic of a Mott insulator. This regime requires a small lattice spacing of ~500 nm. ● Quantum Gas Microscope The blue arrows show the lattice creation path. The orange arrows show the imaging path. -Laser light forms the lattice potential after entering the periodic mask -Light shined on the atoms causes them to fluoresce -The light then travels into a vacuum chamber where it is projected onto the 2D atom sample -This scattered fluorescence light is collected by the lens and captured by the CCD camera Brightness histogram: the left peak represents empty sites, and the right peak sites occupied by a single atom. Photon counts for sparse site occupation of optical lattice Summary Identification of single atoms in a high-resolution image1. The quantum gas microscope allows us to: 1,2 detect and trace single atoms in strongly correlated systems ● simulate Hamiltonians by creating arbitrary potentials 3 ● create and control large scale quantum information systems [1] J. F. Sherson et al. Single-atom-resolved fluorescence imaging of an atomic Mott insulator. Nature Phys. 467; [2] W. S. Bakr et al. Probing the Superfluid-to-Mott Insulator Transition at the Single-Atom Level. Science 329; [3] B. Capogrosso-Sansone et al. Quantum Phases of Cold Polar Molecules in 2D Optical Lattices. Phys. Rev. Lett. 104. Acknowledgements. We acknowledge the real authors of the paper, “A quantum gas microscope for detecting single atoms in a Hubbard-regime optical lattice” (Nature, 462:74-77 [2009]) Waseem Bakr, Jonathon Gillen, Amy Peng, et al.