Traditional mirrors work by directing the path of photons of light but atoms possessing a magnetic moment can likewise be controlled using a magnetic mirror. A new study investigates the feasibility of using magnetic domain walls to direct and ultimately trap individual atoms in a cloud of ultracold atoms.
We have investigated pinning potentials created by inter-domain wall magnetostatic interactions in planar magnetic nanowires. We show that these potentials can take the form of an energy barrier or an energy well depending on the walls’ relative monopole moments, and that the applied magnetic fields required to overcome these potentials are significant. Both transverse and vortex wall pairs are investigated and it is found that transverse walls interact more strongly due to dipolar coupling between their magnetization structures. Simple analytical models which allow the effects of inter-domain wall interactions to be estimated are also presented.
The researchers are describing the design, fabrication and characterization of a mirror formed by the magnetic field created by domain walls within an array of undulating planar magnetic nanowires. Due to the undulation of the wires, the field is switchable. When a magnetic field is applied perpendicular to the wires, the domain walls switches on; when a field is applied parallel to the wires, the switch turns off. Essentially, the system becomes a logical mirror with 0 and 1 states.
"We are looking for ways to build magnetic systems that can manipulate atoms," says author Thomas Hayward of the University of Sheffield in the United Kingdom. "By using soft ferromagnetic materials, in the form of nanostructures, we can manipulate the material properties and direct atoms. The next step is to drop a cloud of ultracold atoms on the mirror so that we can watch them bounce."
Similar technology could be applied to devices that trap and confine atoms and possibly to devices that use individual atoms as qubits.
Citation: T. J. Hayward, M. T. Bryan, P. W. Fry, P. M. Fundi, M. R. J. Gibbs, M.-Y. Im, P. Fischer, and D. A. Allwood, 'Pinning induced by inter-domain wall interactions in planar magnetic nanowires', Appl. Phys. Lett. 96, 052502 (2010); doi:10.1063/1.3275752
