Frequency-dependent squeezing for gravitational-wave detection through quantum teleportation

Ground-based interferometric gravitational wave detectors are highly precisesensors for weak forces, limited in sensitivity across their detection band byquantum fluctuations of light. Current and future instruments address thislimitation by injecting frequency-dependent squeezed vacuum into the detectionport, utilizing narrow-band, low-loss optical cavities for optimal rotation ofthe squeezing ellipse at each signal frequency. This study introduces a novelscheme employing the principles of quantum teleportation and entangled statesof light. It allows achieving broadband suppression of quantum noise in detunedsignal recycled-Fabry-Perot--Michelson interferometers, which is the baselinedesign of the low-frequency detector within the Einstein Telescope xylophonedetector, without requiring additional filter cavities or modifications to thecore optics of the main interferometer.