Baseband detection of bistatic electron spin signals in magnetic resonance force microscopy

In magnetic resonance force microscopy (MRFM), it is hypothesized that it is possible to detect the presence of a single electron spin in a sample volume by measuring spin-induced at-tonewton forces using a micromachined cantilever. In the oscillating cantilever driven adiabatic reversals (OSCAR) method for single-spin MRFM, electron spins are manipulated by an external radio-frequency (RF) magnetic field to produce small periodic deviations in the resonant frequency of the cantilever. These deviations can be detected by frequency demodulation followed by a filtered energy detector. In this paper, we present an alternative to energy detection methods, based on optimal detection theory and Gibbs sampling. Receiver operating characteristic (ROC) curves and power curves from simulations are shown for realistic MRFM operating conditions. Surprisingly, the proposed detector performs almost identically to the filtered energy detector for the range of conditions we studied.