ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,442,872, issued on Oct. 14, was assigned to Q.ANT GMBH (Stuttgart, Germany).
"Magnetic field gradiometer" was invented by Robert Roelver (Calw, Germany), Stefan Hengesbach (Stuttgart, Germany) and Michael Foertsch (Ansbach, Germany).
According to the abstract* released by the U.S. Patent & Trademark Office: "A magnetic field gradiometer for determining a magnetic field gradient includes at least one excitation light source for emitting excitation light, and two spatially spaced-apart measuring areas for magnetic field measurement. Color centers in diamond are arranged in the two measuring areas. The color centers emit fluorescent light upon excitation using the excitation light. The ...