Physics Program Presents
Expanding Our Gravitational View of the Universe with Quantum Interferometry
Friday, March 31, 2023
Hegeman 107
12:00 pm – 1:00 pm EDT/GMT-4
12:00 pm – 1:00 pm EDT/GMT-4
Victoria Xu, Massachusetts Institute of Technology
From atom interferometry to laser interferometry, experiments are leveraging quantum mechanics to expand our gravitational view of the Universe. In atom interferometry, we have realized ultra-long coherence times for atoms in spatially-separated superpositions, which can be used for precision table-top tests of exotic physics and gravity. In laser interferometry, as one of the most sensitive instruments ever built, the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO) operates at the limit of quantum noise to detect gravitational waves (GWs) from cataclysmic cosmic events, such as the mergers of black hole and neutron star binaries. Already, the detectors inject quantum light (“squeezed” vacuum) to reduce the high-frequency quantum noise from shot noise. Major upgrades have now been commissioned to additionally reduce the excess low-frequency quantum noise from opto-mechanical backaction. This involves coupling our squeezed light source to a 300-m long, narrow-band, optical “filter” cavity, which rotates the squeezing quadrature below 100 Hz to evade low-frequency quantum noise in the astrophysically-critical band. This low-frequency squeeze rotation will at last configure the LIGO interferometers for optimal sensing, capable of exceeding the standard quantum limit to our measurement sensitivity. In the next observing run of Advanced LIGO, our quantum-enhanced sensitivity will expand the observable horizon of GW astronomy by 70%, expected to bring GW detection from a near-weekly to near-daily occurrence just 9 years after the dawn of GW astronomy.For more information, call 845-758-6822, or e-mail [email protected].
Time: 12:00 pm – 1:00 pm EDT/GMT-4
Location: Hegeman 107