Abstract
Understanding the complexity of the brain ultimately requires insight into the decoding of local microcircuit functionality by noninvasive approaches. Recently, the new field of Spintronics is attracting a lot of attention with its noninvasive abilities to sense the magnetic field of neurons and to modulate their firing with spintronics devices. The two emerging tools are transcranial magnetic stimulation (TMS) and magnetic encephalography (MEG). The proposed nano-TMS device will use magnetic nanowires—the electromagnetic coils’ nanoscale cousins—to generate focused and programmable magnetic fields. Preliminary theoretical calculations show that proposed devices can provide programmable, focused stimulation for noninvasive neuromodulation of neural microcircuits with unprecedented high spatial and temporal resolutions. The nano-MEG is based on a simple version of the magnetometer capable of imaging the neural connections in the brain. The proposed magnetometer will realize the simple quantum limit (SQL) of the ferromagnetic resonance (FMR) of a “YIG” oscillator and/or spin-torque nano-oscillators (STNO) using a phase-locked loop (PLL) synchronized to a quartz clock. This micro-to-nano-metric technology is comparable with silicon integrated circuits and promises a “laboratory on a chip” approach to MEG that permits millions of detectors to be used. The design is aimed at reducing the massive magnetic screening associated with the usual superconducting quantum interference devices (SQUID) or optically pumped magnetometers (OPM).