|If an atomic vapour of bosons is cold and dense enough that the inter-atomic spacing approaches the thermal de Broglie wavelength, then a phase transition occurs and all of the atoms coalesce into the same (lowest energy) quantum state. Such a Bose-Einstein condensate (BEC), in which all of the atoms behave in essentially the same way, is thus the atomic analogue of a laser – an atom laser. These atom lasers are extremely cold (~10nK) coherent macroscopic quantum objects large enough to be observed on a simple CCD camera – bringing textbook quantum mechanics to life. Achievements in the field to date ensured the 2001 Nobel Physics Prize for those who first experimentally realised BEC.|
|In 2003 we created the first BEC in Scotland at Strathclyde, joining other groups worldwide, and in 2005 we made one of the world’s first BEC-in-a-ring experiments. Since 2013 we have a new dipole-trap based BEC experiment with magnetic levitation. Our condensates contain a few 105 87Rb atoms in the |F=2,mF=2> state. We like to measure things with our BECs using interferometry, and split and recombine our condensate atoms using either a Young’s slits arrangement with a magnetic trap and optical plug, or a Mach-Zehnder arrangement using Kapitza-Dirac beams that’s sensitive to magnetic gradients and inertial accelerations of a few mG/cm or cm/s2, respectively.|
Fresnel zone plates: We continue to have a strong interest in ring geometries as a means to achieve precision guided matter-wave interferometry. In addition to a variety of one- and two-dimensional micro-fabricated spatially periodic patterns (gratings), we are investigating the use of micro-fabricated transmissive Fresnel holograms for creating arbitrary optical dipole potentials for atomtronics.
Funding: EPSRC grants EP/M013294/1, EP/G026068/1, GR/N21000/01, ESA 4000120052/17/NL/BJ, DSTL DSTLX1000095638R, Leverhulme Trust RPG-2013-074, InnovateUK EP/R002371/1.
Publications: ultracold rings and interferometers
- V.A. Henderson, M.Y.H. Johnson, Y.B. Kale, P.F. Griffin, E. Riis, and A.S. Arnold, Optical characterisation of micro-fabricated Fresnel zone plates for atomic waveguides, Opt. Express 28, 9072-9081 (2020).
- Y. Zhai, C.H. Carson, V.A. Henderson, P.F. Griffin, E. Riis & A.S. Arnold, Talbot-enhanced, maximum-visibility imaging of condensate interference, Optica 5, 80-85 (2018).
- B.I. Robertson, A.R. MacKellar, J. Halket, A. Gribbon, J.D. Pritchard, A.S. Arnold, E. Riis & P.F. Griffin, Detection of applied and ambient forces with a matterwave magnetic-gradiometer, Phys. Rev. A 96, 053622 (2017).
- V.A. Henderson, P.F. Griffin, E. Riis & A.S. Arnold, Comparative simulations of Fresnel holography methods for atomic waveguides, New J. Phys. 18, 025007 (2016).
- G.A. Sinuco-León, K.A. Burrows, A.S. Arnold & B.M. Garraway, Inductively guided circuits for ultracold dressed atoms, Nature Comm. 5, 5289 (2014).
- M. Vangeleyn, B.M. Garraway, H. Perrin & A.S. Arnold, Inductive dressed ring traps for ultracold atoms, J. Phys. B 47, 071001 (2014).
- J.D. Pritchard, A.N. Dinkelaker, A.S. Arnold, P.F. Griffin & E. Riis, Demonstration of an inductively coupled ring trap for cold atoms, New J. Phys. 14, 103047 (2012).
- M.E. Zawadzki, P.F. Griffin, E. Riis & A.S. Arnold, Spatial interference from well-separated split condensates, Phys. Rev. A 81, 043608 (2010).
- N. Houston, E. Riis & A.S. Arnold, Reproducible dynamic dark ring lattices for ultracold atoms, J. Phys. B 41, 211001 (2008).
- P.F. Griffin, E. Riis & A.S. Arnold, Smooth inductively coupled ring trap for atoms, Phys. Rev. A 77, 051402(R) (2008).
- A.S. Arnold, C.S. Garvie & E. Riis, Large magnetic storage ring for Bose-Einstein condensates, Phys. Rev. A 73, 041606(R), (2006).
- A.S. Arnold, Adaptable-radius, time-orbiting magnetic ring trap for Bose-Einstein condensates, J. Phys. B 37, L29 (2004).
- A.S. Arnold & E. Riis, Bose-Einstein condensates in ‘giant’ toroidal magnetic traps, J. Mod. Opt. 49, 959 (2002).