Uncooled, millimeter-scale atomic magnetometers with femtotesla sensitivity

We summarize recent results at NIST to develop high-performance yet highly miniaturized magnetic sensors based on atomic vapors confined in microfabricated alkali vapor cells. These sensors currently achieve sensitivities in the range of a few tens of femtotesla in a 1 Hz bandwidth in detection volumes of about 1 mm 3 . They require no cooling and only a small amount of heating, making them ideal for deployment in remote, power starved locations.