Quantum Teleportation for Full-Bandwidth Noise Reduction in Gravitational Wave Detectors

by Dr Andrea Grimaldi (Niels Bohr Institute, University of Copenhagen)

Wednesday 18 Dec 2024, 11:00 → 13:00 Europe/Rome

P2B (Dipartimento di Fisica e Astronomia - Edificio Paolotti)

Broadband quantum noise reduction is a fundamental challenge in the development of next-generation Gravitational Wave Detectors (GWDs). In detuned signal-recycled Fabry-Pérot–Michelson interferometers, the optical spring effect introduces a second resonance, which traditionally requires an additional Filter Cavity to implement Frequency-Dependent Squeezing (FDS). While effective, this approach significantly increases financial costs and technological complexity.

Recent theoretical work proposes an alternative strategy based on Quantum Teleportation, offering a novel pathway to suppress quantum noise. This method utilizes conditional EPR entanglement to create phase rotations in optical fields frequency-shifted from the interferometer carrier frequency, ω₀​. The first phase rotation is introduced by single-mode squeezing offset by ΔΩ_B​, generating an initial FDS state. A second rotation is achieved through a Frequency-Dependent entanglement link, wherein an entangled idler field at ω₀+ΔΩ_A​ interacts with the FDS state. Bell-state measurement facilitates the projection of the idler’s phase properties onto the FDS state, enabling the teleportation of double-rotated squeezing to ω₀.

This approach promises full-bandwidth quantum noise suppression for detuned interferometers without modifying the detector’s existing infrastructure. Beyond its practical implications, this method demonstrates how quantum communication protocols can be reinterpreted as advanced sensing tools, marking a paradigm shift in the intersection of quantum optics and gravitational wave detection.