The LIGO Scientific Collaboration has developed and implemented a new method, called frequency-dependent squeezing, to significantly reduce quantum noise in gravitational wave detectors. By manipulating quantum fluctuations using this advanced technique, they have extended the range of detectable gravitational wave frequencies, increasing the volume of the universe that can be probed by up to 65%. This improvement allows the detection of more black hole and neutron star mergers, providing clearer signals for studying phenomena such as orbital precession, eccentricity and possible deviations from general relativity. The method, which involves tailor-made squeezing at different frequencies, marks a remarkable advance in quantum state manipulation and paves the way for future, more sensitive gravitational wave detectors.

https://physics.aps.org/articles/v16/189