Nuclear magnetic resonance force microscopy with a microwire rf source

摘要

The authors use a 1.0 μm wide patterned Cu wire with an integrated nanomagnetic tip to measure the statistical nuclear polarization of ~(19)F in CaF_2 by magnetic resonance force microscopy. With less than 350 μW of dissipated power, the authors achieve rf magnetic fields over 4 mT at 115 MHz for a sample positioned within 100 nm of the "microwire" rf source. A 200 nm diameter FeCo tip integrated onto the wire produces field gradients greater than 10~5 T/m at the same position. The large rf fields from the broadband microwire enable long rotating-frame spin lifetimes of up to 15 s at 4 K.