Robert J. C. Spreeuw

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We localize Cs atoms in wavelength-sized potential wells of an optical lattice, and cool them to a three-dimensional temperature of 700 nK by adiabatic expansion. In the optical lattice we precool the atoms to ø1 mK. We then reduce the trapping potential in a few hundred ms, causing the atomic center-of-mass distribution to expand and the temperature to(More)
We report on an experiment on Grover's quantum search algorithm showing that classical waves can search a N-item database as efficiently as quantum mechanics can. The transverse beam profile of a short laser pulse is processed iteratively as the pulse bounces back and forth between two mirrors. We directly observe the sought item being found in(More)
We show that three-body loss of trapped atoms leads to sub-Poissonian atom-number fluctuations. We prepare hundreds of dense ultracold ensembles in an array of magnetic microtraps which undergo rapid three-body decay. The shot-to-shot fluctuations of the number of atoms per trap are sub-Poissonian, for ensembles comprising 50-300 atoms. The measured(More)
We present two different strategies for developing a quantum information science platform, based on our experimental results with magnetic microtrap arrays on a magnetic-film atom chip. The first strategy aims for mesoscopic ensemble qubits in a lattice of ∼5μm period, so that qubits can be individually addressed and interactions can be mediated by Rydberg(More)
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We describe the fabrication and construction of a setup for creating lattices of magnetic microtraps for ultracold atoms on an atom chip. The lattice is defined by lithographic patterning of a permanent magnetic film. Patterned magnetic-film atom chips enable a large variety of trapping geometries over a wide range of length scales. We demonstrate an atom(More)
We demonstrate a new and efficient laserlocking technique that enables making large frequency jumps while keeping the laser in lock. A diode laser is locked at a variable offset from a Doppler-free spectral feature of rubidium vapor. This is done by frequency shifting the laser before sending the light to a spectroscopy cell with an acousto-optic modulator(More)
We present new results on an optical implementation of Grover’s quantum search algorithm. This extends previous work in which the transverse spatial mode of a light beam oscillates between a broad initial input shape and a highly localized spike, which reveals the position of the tagged item. The spike reaches its maximum intensity after N round trips in a(More)
We present designs for Ioffe-Pritchard type magnetic traps using planar patterns of hard magnetic material. Two designs are based on 40 μm foil of FePt. The first sample yields calculated axial and radial trap frequencies of 51 Hz and 6.8 kHz, respectively. For the second sample the calculated frequencies are 34 Hz and 11 kHz. The structures were produced(More)
In this paper we show that the sensitivity of absorption imaging of ultracold atoms can be significantly improved by imaging in a standing-wave configuration. We present simulations of single-atom absorption imaging both for a travelling-wave and a standing-wave imaging setup, based on a scattering approach to calculate the optical density of a single atom.(More)