  One of the major challenges in performing SQUID-detected Magnetic Resonance
Force Microscopy (MRFM) at milliKelvin temperatures is the crosstalk between
the radiofrequency (RF) pulses used for the spin manipulation and the
SQUID-based detection mechanism. Here we present an approach based on balancing
the flux crosstalk using an on-chip feedback coil coupled to the SQUID. This
approach does not require any additional components near the location of the
sample, and can therefore be applied to any SQUID-based detection scheme to
cancel predictable RF interference. We demonstrate the effectiveness of our
approach by showing that we can almost completely negate flux crosstalk with an
amplitude of up to several $\Phi_0$. This technical achievement allows for
complicated magnetic resonance protocols to be performed at temperatures below
50 mK.
