Chinese-German team develops ultra-sensitive floating compass to search for dark matter

A Chinese-German research team has built a tabletop magnetic sensor that works like a compass, but with its needle floating in mid-air.

The Levitated Magnet Magnetometer, or LeMaMa, operates at room temperature and can detect magnetic signals a billion times fainter than Earth’s own magnetic field. Its needle moves with virtually no friction, allowing researchers to track extremely small deflections.

The team says the instrument can measure magnetic fields down to the femtotesla level. That advance could expand efforts to detect elusive dark matter particles by making it possible to search for exceptionally faint magnetic signals.