Atomic magnetometer-based high-sensitivity multichannel magnetic sensor

Multichannel parallel magnetic measurements are required for various applications in many fields such as neuroscience and biomedical research. The leading high-sensitivity multichannel sensors are based on arrays of a low-temperature superconducting quantum interference device (SQUID) magnetometer, which presents multiple technological challenges mainly due to cryogenic operation and a high cost. In order to improve the current technologies of multichannel sensors, we recently constructed a highly sensitive 16-channel magnetic sensor based on an atomic magnetometer. The multichannel operation is based on a single large Rb vapor cell, two broad laser beams, and a two dimensional photodiode array. In this talk, we will describe the basic principle and the design of our multichannel sensor. We experimentally demonstrate that each channel of the sensor has a high sensitivity of a few tens femtotesla at low frequency. We anticipate that this sensor will be useful for many applications.