Comment on “a Dynamic Electric Trap for Ground-State Atoms”

Erling Riis, Stephen Mark Barnett

A new type of trap for ground-state atoms is proposed. It is based on the balancing of gravity and the electric-dipole attraction between the polarisable atom and a slowly oscillating electric charge. The stability of this dynamic trap is predicted for a narrow range of operating conditions. However, practical considerations result in a trap depth only comparable to the lowest temperatures routinely obtained with laser-cooled atoms.

E. Peik

Jacques Pinard

Frederic Hummel, Kevin Keiler, Peter Schmelcher

We investigate the quantum dynamics of ultra-long-range trilobite molecules exposed to homogeneous electric fields. A trilobite molecule consists of a Rydberg atom and a ground-state atom, which is trapped at large internuclear distances in an oscillatory potential due to scattering of the Rydberg electron off the ground-state atom. Within the Born-Oppenheimer approximation, we derive an analytic expression for the two-dimensional adiabatic electronic potential energy surface in weak electric fields valid up to 500 V/m. This is used to unravel the molecular quantum dynamics employing the multiconfigurational time-dependent Hartree method. Quenches of the electric field are performed to trigger the wave-packet dynamics including the case of field inversion. Depending on the initial wave packet, we observe radial intrawell and interwell oscillations as well as angular oscillations and rotations of the respective one-body probability densities. Opportunities to control the molecular configuration are identified, a specific example being the possibility to superimpose different molecular bond lengths by a series of periodic quenches of the electric field.

S. D. Hogan, E. Vliegen, Daniel Sprecher +6 more

Argon and hydrogen atoms excited to Rydberg Stark states in supersonic expansions have been decelerated using inhomogeneous electric fields. In the case of hydrogen, the atoms have been decelerated from an initial velocity of 700 m/s to zero velocity in the lab frame using time-dependent inhomogeneous electric fields and subsequently stored in two- and three-dimensional traps. The dynamics of the Rydberg atoms in the traps and the phase-space characteristics of the decelerated atoms have been characterized by pulsed field ionization and imaging techniques. Multi-stage Zeeman deceleration of ground state H and D atoms has been demonstrated. Using this technique H atoms, traveling at 420 m/s, have been decelerated to half of their initial kinetic energy. © 2008 World Scientific Publishing Co. Pte. Ltd.

Wolfgang Ketterle, David E. Pritchard