Harvard researchers create world's smallest radio reciever from atomic scale defects in a diamond

Harvard researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have built the world’s smallest radio receiver , made out of atomic scale defects in pink diamonds. The tiny radio is robust and biocompatible, which means it can be used in all sorts of extreme applications, from a space probe headed to Venus to a pacemaker embedded in a human body. The radio is based on nitrogen vacancy centres, with one carbon atom placed in a tiny diamond with a nitrogen atom and removing the neighbouring atom. The nitrogen vacancy centres are then powered by a green laser. The electrons in the nitrogen vacancy centre are sensitive to electromagnetic waves, including FM signals. When the electrons in a nitrogen vacancy centre receive radio waves, they convert the radio waves and emit streams of red light. This red light stream can be interpreted with a photodiode, that converts the stream of light into a current, which can be converted to sound and heard on conventional speakers.

An electromagnet placed around the diamond can be used to tune in to a particular radio station. Billions of nitrogen vacancy centers can be used to boost the signal, but the radio works even with a single nitrogen vacancy center, emitting one photon at a time. The nitrogen vacancy centers can convert information into light, which potentially allows such tiny structures to be used in photonics, sensors and quantum computers.