  Ground-based interferometric gravitational wave detectors are highly precise
sensors for weak forces, limited in sensitivity across their detection band by
quantum fluctuations of light. Current and future instruments address this
limitation by injecting frequency-dependent squeezed vacuum into the detection
port, utilizing narrow-band, low-loss optical cavities for optimal rotation of
the squeezing ellipse at each signal frequency. This study introduces a novel
scheme employing the principles of quantum teleportation and entangled states
of light. It allows achieving broadband suppression of quantum noise in detuned
signal recycled-Fabry-Perot--Michelson interferometers, which is the baseline
design of the low-frequency detector within the Einstein Telescope xylophone
detector, without requiring additional filter cavities or modifications to the
core optics of the main interferometer.
