  We report theoretical and experimental work on the development of a vortex
qubit based on a microshort in an annular Josephson junction. The microshort
creates a potential barrier for the vortex, which produces a double-well
potential under the application of an in-plane magnetic field; The field
strength tunes the barrier height. A one-dimensional model for this system is
presented, from which we calculate the vortex depinning current and attempt
frequency as well as the interwell coupling. Implementation of an effective
microshort is achieved via a section of insulating barrier that is locally
wider in the junction plane. Using a junction with this geometry we demonstrate
classical state preparation and readout. The vortex is prepared in a given
potential well by sending a series of "shaker" bias current pulses through the
junction. Readout is accomplished by measuring the vortex depinning current.
