Hannover 2020 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 28: Precision Measurements and Metrology (Gravity)
Q 28.7: Talk
Wednesday, March 11, 2020, 12:30–12:45, f435
Effective negative-mass oscillator for coherent quantum noise cancellation — •Jonas Junker1,2,3, Daniel Steinmeyer1,2,3, Dennis Wilken1,2,3, and Michèle Heurs1,2,3 — 1Max Planck Institute for Gravitational Physics, and Institute for Gravitational Physics, Germany — 2QuantumFrontiers — 3PhoenixD
In opto-mechanical measurements, like in gravitational wave detectors, quantum radiation pressure noise is one of the fundamental limitations of low-frequency sensitivity. The concept of coherent quantum noise cancellation proposes to add an effective negative-mass oscillator to such a measurement system. Thus, the back-action effect caused by the quantum radiation pressure can ideally be evaded and the standard quantum limit is surpassed. In our all-optical setup, the negative-mass oscillator is implemented by a detuned optical cavity that is coupled via a beam splitter and a down conversion interaction to the light field. It needs to be matched in resonance frequency, damping and coupling strengths to the measurement system. We present the theoretical background of coherent quantum noise cancellation. Additionally, we show for which realistic conditions the negative-mass oscillator can reduce back-action noise introduced by a positive mass micromechanical oscillator (see contribution by Bernd Schulte). We explain the setup of our negative-mass oscillator consisting of a five-mirror cavity where both polarisation modes are coupled by a wave-plate as beam splitter interaction. A nonlinear crystal is placed in the cavity; this is a polarisation non-degenerate two-mode squeezing process. We will present the current status of the experiment and planned next steps.