Detection of an electron spin in a MRFM cantilever experiment

In the magnetic resonance force microscopy (MRFM) experiment that we consider, a cantilever is used to detect the presence of an electron spin. If an electron spin is present, the equation governing the motion of the cantilever is nonlinear. In the absence of a spin, the equation is linear. We propose a detector model that uses two Kalman filter (KF) state estimators. The estimator for the spin hypothesis is an adaptation of the standard KF, and can be viewed as a 0th order mixed-time extended Kalman filter (EKF). Simulation results are presented for several system parameter values.