Professor Christopher Foot: Publications

Time-averaged adiabatic ring potential for ultracold atoms

(2011)

Authors:

BE Sherlock, M Gildemeister, E Owen, E Nugent, CJ Foot

Time-averaged adiabatic ring potential for ultracold atoms (vol 83, 043408, 2011)

PHYSICAL REVIEW A 83:5 (2011) ARTN 059904

Authors:

BE Sherlock, M Gildemeister, E Owen, E Nugent, CJ Foot

Ultracold atoms in an optical lattice with dynamically variable periodicity

Physical Review A - Atomic, Molecular, and Optical Physics 82:2 (2010)

Authors:

S Al-Assam, RA Williams, CJ Foot

Abstract:

The use of a dynamic "accordion" lattice with ultracold atoms is demonstrated. Ultracold atoms of Rb87 are trapped in a two-dimensional optical lattice, and the spacing of the lattice is then increased in both directions from 2.2 to 5.5 μm. Atoms remain bound for expansion times as short as a few milliseconds, and the experimentally measured minimum ramp time is found to agree well with numerical calculations. This technique allows an experiment such as quantum simulations to be performed with a lattice spacing smaller than the resolution limit of the imaging system, while allowing imaging of the atoms at individual lattice sites by subsequent expansion of the optical lattice. © 2010 The American Physical Society.

Ultracold atoms in an optical lattice with dynamically variable periodicity

(2010)

Authors:

S Al-Assam, RA Williams, CJ Foot

Trapping ultracold atoms in a time-averaged adiabatic potential

Physical Review A - Atomic, Molecular, and Optical Physics 81:3 (2010)

Authors:

M Gildemeister, E Nugent, BE Sherlock, M Kubasik, BT Sheard, CJ Foot

Abstract:

We report an experimental realization of ultracold atoms confined in a time-averaged, adiabatic potential (TAAP). This trapping technique involves using a slowly oscillating (∼kHz) bias field to time-average the instantaneous potential given by dressing a bare magnetic potential with a high-frequency (~MHz) magnetic field. The resultant potentials provide a convenient route to a variety of trapping geometries with tunable parameters. We demonstrate the TAAP trap in a standard time-averaged orbiting potential trap with additional Helmholtz coils for the introduction of the radio frequency dressing field. We have evaporatively cooled 5×104 atoms of Rb87 to quantum degeneracy and observed condensate lifetimes of longer than 3 s. © 2010 The American Physical Society.

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