Designing lattices for ultracold atoms

Roman Schmied, Dietrich G. Leibfried, R. J. C. Spreeuw +1 more

We introduce a general method for designing tailored lattices of magnetic microtraps for ultracold atoms on the basis of patterned permanently magnetized films. A fast numerical algorithm is used to automatically generate patterns that provide optimal atom confinement while respecting desired lattice symmetries and trap parameters. The algorithm can produce finite and infinite lattices of any plane symmetry; we focus specifically on square and triangular lattices, which are of interest for future experiments. Typical trap parameters, as well as the impact of realistic imperfections such as finite lithographic resolution and magnetic inhomogeneity, are discussed. The designer lattices presented open new avenues for quantum simulation and quantum information processing with ultracold atoms on atom chips.

Gaia Donati

Tien Tran, Yibo Wang, I. Herrera +6 more

In recent years, ultracold atoms trapped in periodic lattices have attracted much attention as a simulator for condensed matter systems because of the ability to manipulate and precisely control the ultracold atoms. Periodic arrays of magnetic microtraps patterned on a magnetic film provide a potential complementary tool to conventional optical lattices for trapping arrays of ultracold atoms. Compared to optical lattices, magnetic lat- tices allow a higher degree of design flexibility by allowing almost arbitrary lattice geometries and they also allow lower technical noise and state-selective trapping of atoms. This paper reports the trapping of ultracold 87Rb atoms in 0.7 μm-period triangular and square magnetic lattices integrated on an atom chip as a step towards using magnetic lattices as a new platform for simulating condensed matter and quantum many-body phenomena in nontrivial lattice geometries.

Gyu-Boong Jo

Martin Shotter

A measurement technique is described that has the potential to map the atomic site occupancies of ultracold atoms in a short-period three-dimensional optical lattice. The method uses accordion and pinning lattices, together with polarization gradient cooling and fluorescence detection, to measure the positions of individual atoms within the sample in three dimensions at a resolution of around half the atomic resonant wavelength. The method measures the site occupancy, rather than the parity of the site occupancy, of atoms in the lattice. It is expected that such measurements hold significant potential for the study of ultracold quantum dynamics.

Immanuel Bloch