Tabletop quantum experiment could detect gravitational waves

Tiny diamond crystals could be used as an incredibly sensitive and small gravitational detector capable of measuring gravitational waves, suggests new UCL-led research. Predicted by Einstein's general theory of relativity, gravitational waves are ripples in space-time generated by certain movements of massive objects. They are important to study because they allow us to detect events in the universe that would otherwise leave little or no observable light, like black hole collisions. In 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo collaborations made the first direct observation of gravitational waves. The waves were emitted from a 1.3 billion-year-old collision between two supermassive black holes and were detected using 4 km long optical interferometers as the event caused ripples in the Earth's space-time. Researchers from UCL, University of Groningen, and University of Warwick propose a detector based on quantum technology that is 4000 times smaller than the detectors currently in use and could detect mid-frequency gravitational waves. The study, published today in New Journal of Physics , details how state-of-the-art quantum technologies and experimental techniques can be used to build a detector capable of measuring and comparing the strength of gravity in two locations at the same time.