Quantum Optics of Ultracold Molecular Fields

We apply concepts of quantum optical coherence to characterize the coherent generation of a molecular field from a quantum-degenerate atomic sample, and discuss the impact of the quantum statistics of the atoms on that field. For atoms initially in a BEC the resulting molecular field is to a good approximation coherent. This is in sharp contrast to the case of atoms in a normal Fermi gas, where we can made use of an analogy with the Tavis-Cummings model to show that the statistics of the resulting molecular field is similar to that of a single-mode chaotic light field. The BCS case interpolates between the two extremes, with an ＇incoherent＇ contribution from unpaired atoms superposed to a ＇coherent＇ contribution from atomic Cooper pairs. We also comment on the temporal fluctuations characteristic of the formation of molecular dimers from ultracold fermionic atoms.

Quantum Optics of Ultracold Molecular Fields

We will describe how cold atoms guided by atom chips may be used to realize quantum registers, ie arrays of quantum bits for quantum information processing. Such atomic realizations have shown much promise for scalable quantum computation. The timescales for manipulating the qubits in a significant way seem well within the relevant decoherence times and look likely to allow the demonstration of simple quantum algorithms. We begin by reviewing the criteria needed for coherent gate manipulation to be completed within a decoherence time and show how atom chips can meet these criteria. We will then describe how optical lattices can generate registers of cold neutral atoms. Finally, we will describe how such cold atom lattices can be manipulated using the magnetic fields within atom chip, offering an integrated register for quantum information processing.