Quantitative Current Evaluation Through Magnetic Field Detection by Magnetic Force Microscopy

We observed magnetic fields induced by a current passing through a fine path by magnetic force microscopy (MFM) in order to investigate the possibility of evaluating the current with high spatial resolution. In particular, we examined the magnetic field around an artificial current network to provide quantitative data on the method when a torsional displacement was imposed on an MFM cantilever by the magnetic force. Although the torsional displacement signal included some background offset, data calibration could be performed by subtracting the background from the original torsional signal, and the data after calibration was compared with the current value expected from the network structure. The calibrated data showed relatively good consistency with the expected value, which indicates the suitability of MFM observation of the magnetic field in quantitative evaluation of current.