A requirement for many quantum computation schemes is the ability to measure
single spins. This paper examines one proposed scheme: magnetic resonance force
microscopy, including the effects of thermal noise and back-action from
monitoring. We derive a simplified equation using the adiabatic approximation,
and produce a stochastic pure state unraveling which is useful for numerical
simulations.Comment: 33 pages LaTeX, 9 figure files in EPS format. Submitted to Physical
Review