We present two novel dressed inductive ring trap geometries, ideal for atom interferometry or studies of superfluidity and well-suited to utilisation in atom chip architectures. The design permits ring radii currently only accessible via near-diffraction-limited optical traps, whilst retaining the ultra-smooth magnetic potential afforded by inductive traps. One geometry offers simple parallel implementation of multiple rings, whereas the other geometry permits axial beam-splitting of the torus suitable for whole-ring atom interferometry. PACS numbers: ar X ivWe present two novel dressed inductive ring trap geometries, ideal for atom interferometry or studies of superfluidity and well-suited to utilisation in atom chip architectures. The design permits ring radii currently only accessible via near-diffraction-limited optical traps, whilst retaining the ultra-smooth magnetic potential afforded by inductive traps. One geometry offers simple parallel implementation of multiple rings, whereas the other geometry permits axial beam-splitting of the torus suitable for whole-ring atom interferometry. PACS numbers: ar X iv

Mar 26, 20147 citations

Ring trap for ultracold atoms

Olivier Morizot, Yves Colombe, V. Lorent +2 more

We propose a toroidal trap designed for ultracold atoms. It relies on a combination of a magnetic trap for rf-dressed atoms, which creates a bubble-like trap, and a standing wave of light. This trap is well-suited for investigating questions of low dimensionality in a ring potential. We study the trap characteristics for a set of experimentally accessible parameters. A loading procedure from a conventional magnetic trap is also proposed. The flexible nature of this ring trap, including an adjustable radius and adjustable transverse oscillation frequencies, will allow the study of superfluidity in variable geometries and dimensionalities.We propose a toroidal trap designed for ultracold atoms. It relies on a combination of a magnetic trap for rf-dressed atoms, which creates a bubble-like trap, and a standing wave of light. This trap is well-suited for investigating questions of low dimensionality in a ring potential. We study the trap characteristics for a set of experimentally accessible parameters. A loading procedure from a conventional magnetic trap is also proposed. The flexible nature of this ring trap, including an adjustable radius and adjustable transverse oscillation frequencies, will allow the study of superfluidity in variable geometries and dimensionalities.

arXiv:physics/0512015Physical Review AAug 23, 2006145 citations

Smooth inductively coupled ring trap for atoms

Paul F. Griffin, Erling Riis, Aidan S. Arnold

We propose and numerically investigate a scalable ring trap for cold atoms that surmounts problems of roughness of the potential and end effects of trap wires. A stable trapping potential is formed about an electrically isolated, conducting loop in an ac magnetic field by time averaging the superposition of the external and induced magnetic fields. We investigate the use of additional fields to eliminate Majorana spin-flip losses and to create a stable trapping geometry. The possibility of microfabrication of these ring traps offers the prospect of developing Sagnac atom interferometry in atom-chip devices.We propose and numerically investigate a scalable ring trap for cold atoms that surmounts problems of roughness of the potential and end effects of trap wires. A stable trapping potential is formed about an electrically isolated, conducting loop in an ac magnetic field by time averaging the superposition of the external and induced magnetic fields. We investigate the use of additional fields to eliminate Majorana spin-flip losses and to create a stable trapping geometry. The possibility of microfabrication of these ring traps offers the prospect of developing Sagnac atom interferometry in atom-chip devices.

arXiv:0803.0940Physical Review AMay 13, 200840 citations

Time-averaged adiabatic ring potential for ultracold atoms

Benjamin E. Sherlock, M. Gildemeister, E. Owen +2 more

We report the experimental realization of a versatile ring trap for ultracold atoms. The ring geometry is created by the time-averaged adiabatic potential resulting from the application of an oscillating magnetic bias field to a rf-dressed quadrupole trap. Lifetimes for a Bose-Einstein condensate in the ring exceed $11\mathrm{s}$ and the ring radius was continuously varied from $50 \ensuremath{\mu}\text{m}$ to $262 \ensuremath{\mu}\text{m}$. An efficient method of loading the ring from a conventional time-averaged orbiting potential trap is presented together with a rotation scheme which introduces angular momentum into the system. The ring presents an opportunity to study the superfluid properties of a condensate in a multiply connected geometry and also has applications for matter-wave interferometry.We report the experimental realization of a versatile ring trap for ultracold atoms. The ring geometry is created by the time-averaged adiabatic potential resulting from the application of an oscillating magnetic bias field to a rf-dressed quadrupole trap. Lifetimes for a Bose-Einstein condensate in the ring exceed $11\mathrm{s}$ and the ring radius was continuously varied from $50 \ensuremath{\mu}\text{m}$ to $262 \ensuremath{\mu}\text{m}$. An efficient method of loading the ring from a conventional time-averaged orbiting potential trap is presented together with a rotation scheme which introduces angular momentum into the system. The ring presents an opportunity to study the superfluid properties of a condensate in a multiply connected geometry and also has applications for matter-wave interferometry.

arXiv:1102.2895Physical Review AApr 18, 2011154 citations

Recent developments in trapping and manipulation of atoms with adiabatic potentials

B. M. Garraway, Hélène Perrin

A combination of static and oscillating magnetic fields can be used to 'dress' atoms with radiofrequency (RF), or microwave, radiation.The spatial variation of these fields can be used to create an enormous variety of traps for ultra-cold atoms and quantum gases.This article reviews the type and character of these adiabatic traps and the applications which include atom interferometry and the study of low-dimensional quantum systems.We introduce the main concepts of magnetic traps leading to adiabatic dressed traps.The concept of adiabaticity is discussed in the context of the Landau-Zener model.The first bubble trap experiment is reviewed together with the method used for loading it.Experiments based on atom chips show the production of double wells and ring traps.Dressed atom traps can be evaporatively cooled with an additional RF field, and a weak RF field can be used to probe the spectroscopy of the adiabatic potentials.Several approaches to ring traps formed from adiabatic potentials are discussed, including those based on atom chips, time-averaged adiabatic potentials and induction methods.Several proposals for adiabatic lattices with dressed atoms are also reviewed.A combination of static and oscillating magnetic fields can be used to 'dress' atoms with radiofrequency (RF), or microwave, radiation.The spatial variation of these fields can be used to create an enormous variety of traps for ultra-cold atoms and quantum gases.This article reviews the type and character of these adiabatic traps and the applications which include atom interferometry and the study of low-dimensional quantum systems.We introduce the main concepts of magnetic traps leading to adiabatic dressed traps.The concept of adiabaticity is discussed in the context of the Landau-Zener model.The first bubble trap experiment is reviewed together with the method used for loading it.Experiments based on atom chips show the production of double wells and ring traps.Dressed atom traps can be evaporatively cooled with an additional RF field, and a weak RF field can be used to probe the spectroscopy of the adiabatic potentials.Several approaches to ring traps formed from adiabatic potentials are discussed, including those based on atom chips, time-averaged adiabatic potentials and induction methods.Several proposals for adiabatic lattices with dressed atoms are also reviewed.

Journal of Physics B Atomic Molecular and Optical PhysicsAug 22, 201694 citations

Demonstration of an inductively coupled ring trap for cold atoms

J D Pritchard, A N Dinkelaker, A S Arnold +2 more

We report the first demonstration of an inductively coupled magnetic ring trap for cold atoms. A uniform, ac magnetic field is used to induce current in a copper ring, which creates an opposing magnetic field that is time-averaged to produce a smooth cylindrically symmetric ring trap of radius 5 mm. We use a laser-cooled atomic sample to characterize the loading efficiency and adiabaticity of the magnetic potential, achieving a vacuum-limited lifetime in the trap. This technique is suitable for creating scalable toroidal waveguides for applications in matter-wave interferometry, offering long interaction times and large enclosed areas.We report the first demonstration of an inductively coupled magnetic ring trap for cold atoms. A uniform, ac magnetic field is used to induce current in a copper ring, which creates an opposing magnetic field that is time-averaged to produce a smooth cylindrically symmetric ring trap of radius 5 mm. We use a laser-cooled atomic sample to characterize the loading efficiency and adiabaticity of the magnetic potential, achieving a vacuum-limited lifetime in the trap. This technique is suitable for creating scalable toroidal waveguides for applications in matter-wave interferometry, offering long interaction times and large enclosed areas.

arXiv:1207.4225New Journal of PhysicsOct 30, 201230 citations

11\mathrm{s}

and the ring radius was continuously varied from $50 \ensuremath{\mu}\text{m}$ to $262 \ensuremath{\mu}\text{m}$. An efficient method of loading the ring from a conventional time-averaged orbiting potential trap is presented together with a rotation scheme which introduces angular momentum into the system. The ring presents an opportunity to study the superfluid properties of a condensate in a multiply connected geometry and also has applications for matter-wave interferometry.