Quantum Optics Seminar by Farid Khalili

Beating the Standard Quantum Limit in gravitational wave detectors using the negative mass spin system.

Using an additional spin system with the negative effective mass, it is possible to reduce significantly quantum noise in GW detectors [F. Y. Khalili and E. S. Polzik, Phys. Rev. Lett. 121, 031101 (2018)]. However, a simple straightforward version of this approach requires that the effective eigen frequency of the spin system should be close to the one of the pendulum modes of the GW detectors'  mirrors, which could be problematic due to the technological limitations. Here we propose to use the so-called virtual rigidity effect to modify the "perceived" eigen frequency of the spin system. The implementation of this idea requires only the proper tuning of the homodyne and squeezing phases.