9. November 2020

Space Science at Droptower SEMINAR TALK

Location: ZARM Bremen - Online seminar
When: 9.11.2020, 17:00 CET - Online

Speaker: Dennis Rätzel (Humboldt Universität Berlin)
Title: Optimal estimation of time-dependent gravitational fields with quantumoptomechanical systems

Abstract: We study the fundamental sensitivity that can be achieved with an ideal optomechanical system in the nonlinear regime for measurements of time-dependent gravitational fields. Using recently developed methods to solve the dynamics of a nonlinear optomechanical system with a time-dependent Hamiltonian, we compute the quantum Fisher information for linear displacements of the mechanical element due to gravity. In addition, we demonstrate that the sensitivity can not only be further enhanced by injecting squeezed states of the cavity field, but also by modulating the light-matter coupling of the optomechanical system. We specifically apply our results to the measurement of gravitational fields from small oscillating masses, where we show that, in principle, the gravitational field of an oscillating nano-gram mass can be detected based on experimental parameters that willlikely be accessible in the near-term future. Finally, we identify the experimental parameter regime necessary for gravitational wave detection with a quantum optomechanical sensor.