Výsledky vyhledávání

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Observation of two-dimensional Anderson localisation of ultracold atoms

Autor: White, Donald H., Haase, Thomas A., Brown, Dylan J., Hoogerland, Maarten D., Najafabadi, Mojdeh S., Helm, John L., Gies, Christopher, Schumayer, Daniel, Hutchinson, David A. W.

Anderson localisation -- the inhibition of wave propagation in disordered media -- is a surprising interference phenomenon which is particularly intriguing in two-dimensional (2D) systems. While an ideal, non-interacting 2D system of infinite size is

Externí odkaz: http://arxiv.org/abs/1911.04858

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Splitting and recombination of bright-solitary-matter waves

Autor: Wales, Oliver J., Rakonjac, Ana, Billam, Thomas P., Helm, John L., Gardiner, Simon A., Cornish, Simon L.

Solitons are long-lived wavepackets that propagate without dispersion and exist in a wide range of one-dimensional (1D) nonlinear systems. A Bose-Einstein condensate trapped in a quasi-1D waveguide can support bright-solitary-matter waves (3D analogu

Externí odkaz: http://arxiv.org/abs/1906.06083

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Spin-orbit coupled interferometry with ring-trapped Bose--Einstein condensates

Autor: Helm, John L., Billam, Thomas P., Rakonjac, Ana, Cornish, Simon L., Gardiner, Simon A.

Publikováno v: Phys. Rev. Lett. 120, 063201 (2018)

We propose a method of atom-interferometry using a spinor Bose-Einstein condensate (BEC) with a time-varying magnetic field acting as a coherent beam-splitter. Our protocol creates long-lived superpositional counterflow states, which are of fundament

Externí odkaz: http://arxiv.org/abs/1701.02154

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Dissertation/ Thesis

Soliton dynamics in the Gross–Pitaevskii equation : splitting, collisions and interferometry

Autor: Helm, John Lloyd

Bose–Einstein condensates with attractive interactions have stable 1D solutions in the form of bright solitary-waves. These solitary waves behave, in the absence of external potentials, like macroscopic quantum particles. This opens up a wide array

Externí odkaz: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614446

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Bright matter-wave soliton collisions at narrow barriers

Autor: Helm, John L., Billam, Thomas P., Gardiner, Simon A.

Publikováno v: Phys. Rev. A 85, 053621 (2012)

We study fast-moving bright solitons in the focusing nonlinear Schr\"odinger equation perturbed by a narrow Gaussian potential barrier. In particular, we present a general and comprehensive analysis of the case where two fast-moving bright solitons c

Externí odkaz: http://arxiv.org/abs/1203.3080

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