Gravitational-wave astronomy began in 2015 with the first detection of signals from a binary black-hole merger. Since then, LIGO and Virgo have observed more than 300 gravitational-wave events, providing important results in general relativity, astrophysics, and cosmology.
The next generation of gravitational-wave detectors, including the European Einstein Telescope (ET), is currently being developed. These instruments aim for a tenfold improvement in sensitivity compared with LIGO and Virgo, enabling the investigation of fundamental questions related to gravitation, dark energy, nuclear matter, and the formation of neutron stars and black holes throughout cosmic history.
One of the key technologies for achieving this improvement is quantum squeezing, which reduces quantum noise. This noise originates from vacuum fluctuations entering the detector and can be mitigated by replacing the ordinary vacuum with a tailored squeezed vacuum state. Squeezed states, produced through nonlinear optical processes and quantum correlations, have already enhanced Virgo and LIGO. The implementation of frequency-dependent squeezing, using a 300-meter optical cavity to rotate the squeezed quadrature as a function of frequency, now allows noise reduction across the full detection band and has increased the detection rate by up to 65%.
The project aims to develop advanced squeezing techniques for next-generation gravitational-wave detectors, enabling them to reach their targeted sensitivity.
The selected candidate will work primarily on an ANR-funded experiment in the Virgo optics laboratory at APC and will also contribute to improving the quantum squeezing source currently installed in Virgo.