Daniel Higginbottom

Spatial-mode storage in a gradient-echo memory

Three-level atomic gradient echo memory (

Highly efficient optical quantum memory with long coherence time in cold atoms

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Electromagnetically induced transparency and fourwave mixing in a cold atomic ensemble with large optical depth

-GEM) is a proposed candidate for efficient quantum storage and for linear optical quantum computation with time-bin multiplexing [Hosseini et al., Nature (London) 461, 241 (2009)]. In this paper we investigate the spatial multimode properties of a

Pure single photons from a trapped atom source

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Dynamical observations of self-stabilizing stationary light

-GEM system. Using a high-speed triggered CCD, we demonstrate the storage of complex spatial modes and images. We also present an in-principle demonstration of spatial multiplexing by showing selective recall of spatial elements of a stored spin wave. Using our measurements, we consider the effect of diffusion within the atomic vapor and investigate its role in spatial decoherence. Our measurements allow us to quantify the spatial distortion due to both diffusion and inhomogeneous control field scattering and compare these to theoretical models.

Fabrication of ultrahigh-precision hemispherical mirrors for quantum-optics applications

Optical quantum memory is an essential element for long distance quantum communication and photonic quantum computation protocols. The practical implementation of such protocols requires an efficient quantum memory with long coherence time. Beating the no-cloning limit, for example, requires efficiencies above 50\%. An ideal optical fibre loop has a loss of 50% in 100

Wavelength-scale errors in optical localization due to spin–orbit coupling of light

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Highly efficient and long-lived optical quantum memory with cold atoms

s, and until now no universal quantum memory has beaten this time-efficiency limit. Here, we report results of a gradient echo memory (GEM) experiment in a cold atomic ensemble with a 1/e coherence time up to 1ms and maximum efficiency up to 87

Dual-rail optical gradient echo memory

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Gradient Echo Quantum Memory in Warm Atomic Vapor

2% for short storage times. Our experimental data demonstrates greater than 50% efficiency for storage times up to 0.6ms. Quantum storage ability is verified beyond the ideal fibre limit using heterodyne tomography of small coherent states.