Quantum information processing
The emerging field of quantum computation and information processing based on the manipulation of confined ultracold atoms has attracted considerable interest over the last decade.
A degree of confinement can be introduced by using specifically-localised attracting potential minima in an ultra-high vacuum space. An example of this is the periodically-distributed potential minima which are produced by intersecting coherent beams are referred to as the optical lattices.
Integrating the ultra cold atoms with magnetic microstructures has triggered an alternative approach to using optical lattices. A lattice configuration is produced by using periodically distributed non-zero magnetic field local minima to trap ultracold atoms. This produces a pattern which is referred to as a magnetic lattice.
The confining magnetic minima, i.e, the sites of the lattice, are located at working distances above the surface of a patterned permanent magnetic thin film on an atom chip. As with optical lattices, the periodicity can be configured in one or two dimensions. This type of magnetic lattice has the ability to produce highly stable confining magnetic potentials with very low technical noise and may be a suitable candidate for hosting large-scale qubit systems.
Magnetic lattices can also be created using current-carrying wires; however, certain technical difficulties have been encountered, for example, the current produced near-field technical noise can reduce the number of trapped atoms and current density fluctuations across the wire can lead to fragmentation of the cold atom cloud.
Our researchers have overcome these technical difficulties by using permanent magnetic materials which produce stable, reproducible periodic potentials. Several configurations of magnetic lattices have been fabricated and we are currently investigating their performance in collaboration with Advanced Photonics Research Institute, South Korea.
Our aim is to carry out theoretical and experimental research and contribute towards the development of an atom chip for the trapping and confinement of ultracold atoms and quantum degenerate gases.