Jennifer Sebby-Strabley

Lattice of double wells for manipulating pairs of cold atoms

We describe the design and implementation of a two-dimensional optical lattice of double wells suitable for isolating and manipulating an array of individual pairs of atoms in an optical lattice. Atoms in the square lattice can be placed in a double well with any of their four nearest neighbors. The properties of the double well (the barrier height and relative energy offset of the paired sites) can be dynamically controlled. The topology of the lattice is phase stable against phase noise imparted by vibrational noise on mirrors. We demonstrate the dynamic control of the lattice by showing the coherent splitting of atoms from single wells into double wells and observing the resulting double-slit atom diffraction pattern. This lattice can be used to test controlled neutral atom motion among lattice sites and should allow for testing controlled two-qubit gates.

Sublattice addressing and spin-dependent motion of atoms in a double-well lattice.

We load atoms into every site of an optical lattice and selectively spin flip atoms in a sublattice consisting of every other site. These selected atoms are separated from their unselected neighbors by less than an optical wavelength. We also show spin-dependent transport, where atomic wave packets are coherently separated into adjacent sites according to their internal state. These tools should be useful for quantum information processing and quantum simulation of lattice models with neutral atoms.

Preparing and probing atomic number states with an atom interferometer.

We describe the controlled loading and measurement of number-squeezed states and Poisson states of atoms in individual sites of a double well optical lattice. These states are input to an atom interferometer that is realized by symmetrically splitting individual lattice sites into double wells, allowing atoms in individual sites to evolve independently. The two paths then interfere, creating a matter-wave double-slit diffraction pattern. The time evolution of the double-slit diffraction pattern is used to measure the number statistics of the input state. The flexibility of our double well lattice provides a means to detect the presence of empty lattice sites, an important and so far unmeasured factor in determining the purity of a Mott state.

Controlled atom dynamics in a double-well optical lattice

We report on the experimental demonstration of dynamic control of the motional state of atoms in a 2D double-well optical lattice. First we describe experiments in which the atomic distributions obtained by loading Bose–Einstein condensates of rubidium atoms in the lattice are dynamically split by transforming a 2D lattice with period λ into a 2D lattice with period λ/2, and we show how this procedure allows for the study of the coherence and interaction properties of the system. Then we show how we can efficiently adiabatically transfer the population between adjacent sites of the lattice, as well as between different energy bands, by using dynamic modifications of the potential.

Site-selectivity and spin exchange in a double-well optical lattice

We have demonstrated site-selective radio frequency addressing of atoms with subwavelength resolution and a spin-exchange mechanism for a square root of swap gate in a spindependent double-well optical lattice.

A Double Well Lattice for Dynamically Manipulating Pairs of Cold Atoms

We describe the design and implementation of a double-well optical lattice suitable for isolating and manipulating individual pairs of atoms. This lattice will be used to test controlled atom motion and controlled two-qubit gates.