INRIM searches for universe noise exploiting quantum correlations
Researchers at INRIM quantum optics labs, in collaboration with Danish Technical University (DTU), experimentally demonstrated the possibility to explore the weakest fundamental space-time fluctuations, “listening” to some fundamental noises of our universe with the aid of quantum correlations.
Noise, often considered an annoying element also in the measurement field, sometimes has a deep physical meaning. For instance, the cosmic microwave background is a literal echo of cosmic inflation (the rapid expansion of the universe after the Big Bang) that gives insight on the very infancy of our universe. Another type of noise is the gravitational wave background, a random signal related to gravitational waves, that if observed could keep us back in time to the Big Bang itself. In addition, other more exotic faint noises could emerge at Planck-scale, as small as 10-35 m, the limit below which the physical laws that we know cannot be applied.
For the detection of these noises, quantum metrology could be the winning card, exploiting the peculiar effects of quantum mechanics in the measurement science. In a work published by the Nature's group journal Communication Physics, researchers of INRIM (in the frame of EMPIR project 17FUN01 BeCOMe) and DTU demonstrated how to precisely compare the lengths of a pair of Michelson interferometers, sort of table-top scale versions of gravitational-wave detectors, "connected at distance" thanks to the quirks of quantum mechanics. This type of measurement should allow to detect, in principle, extremely tiny differences between the lengths of the two interferometers (as small as 3 X 10-17 m, smaller than a proton radius!) caused by such ineffable space-time distortions.
If detected, this fundamental flickering causing space-time distortions could lead to a revolution in science, connected to a final theory unifying quantum mechanics and gravity and, to some extent, to the holographic principle, describing the universe as a 3D hologram imprinted in a 2D surface.