Progress of Theoretical Physics
Model for Trapped Ion Interacting with Standing Wave via Gauge-Like Transformations
Sher Alam, Cleo L. Bentley
Abstract
We treat the interaction of a trapped ion with a standing-wave light field, relaxing the previous condition of the trapping ion being on the node of the standing wave. In addition we work to second order in the Lamb-Dicke parameter η the extension to higher orders in η is also indicated. Only a simple transformation to the “dressed basis” (subject to the constraint of Pauli algebra) is required in order to show that the ion interacting with a standing light-wave may be described by the Jaynes-Cummings Hamiltonian. The ansatz of leaving invariant the Pauli algebra after the transformations amounts to a linear transformation in the su(2) algebra describing the two level system. The outcome is a Jaynes-Cummings like Hamiltonian with effective coupling dependent on the parameter Χ aimed to figure the trapping location in the standing wave. The main idea, namely leaving the Hamiltonian form invariant while changing the physical parameters can pave the way to a new understanding of gauge like transformations in the present context.