Description du projet
Dépasser la limite quantique fondamentale des détecteurs d’ondes gravitationnelles
Les fluctuations quantiques de la lumière compromettent la sensibilité des détecteurs d’ondes gravitationnelles de prochaine génération. Les principales sources de ces perturbations subtiles sont le bruit de grenaille et le bruit de rétroaction optomécanique. L’évitement de rétroaction est une technique de mesure qui permet de surmonter certaines limites imposées par la mécanique quantique concernant la sensibilité des détecteurs d’ondes gravitationnelles. Un nouveau mécanisme proposé pour supprimer ces deux types de bruit fait appel à un ensemble de spins atomiques comme support de stockage des fluctuations quantiques de la lumière. La mesure de l’évitement de rétroaction est réalisée par deux faisceaux de lumière intriqués qui sondent les détecteurs d’ondes gravitationnelles et l’ensemble de spin. Financé par le programme Actions Marie Skłodowska-Curie, le projet SingletSQL étudiera les questions découlant de la mise en œuvre de cette approche de mesure.
Objectif
The sensitivity of the next-generation gravitational-wave detectors (GWD) are critically limited by the quantum fluctuations of light. The major sources of such noises are shot noise and optomechanical back action noise (BAN). The improvement of sensitivity can be achieved by back-action evading (BAE) measurements, which allows overcoming the standard quantum limit. By trading off between shot and BAN, recently a promising scheme has been proposed which involves another auxiliary system, consisting of an atomic spin ensemble with negative effective mass that can suppress both the noises. The measurement is performed by two entangled beams of light probing the GWD and the spin ensemble. However, the approach exhibits three major implementational issues to focus on, which I have discovered by recent calculations. Firstly, I study how the sensitivity of the GWD is dependent and what the constraints introduced by the entanglement measures between subsystems. Secondly, I come with a novel approach for the BAE by using a nuclear singlet state of carbon in diamond which works at very low NMR frequencies and bandwidth aiming to avoid the discrepancies of the match between the frequencies and linewidths of the spin and the mechanical oscillators. In this aspect, I propose using a novel type readout of electron spin of NV centers, used as a non-perturbing ancilla of the nuclear spin-singlet. Finally, based on the parameters obtained from ongoing E-Test project, where a low thermal noise mechanical oscillator is being built up, I will theoretically investigate if the nuclear singlet state can match the frequency and bandwidth of rational parameters of the oscillator and whether it can be implemented for the BAE measurement. I will study the role played by the input squeezing parameters, and how to engineer the frequency range of noise suppression of the output. The proposal entitles advanced hands-on training on experimental setups and profounding my background in GWD.
Mots‑clés
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Appel à propositions
(s’ouvre dans une nouvelle fenêtre) HORIZON-MSCA-2021-PF-01
Voir d’autres projets de cet appelRégime de financement
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinateur
3001 Leuven
Belgique