Speaker
Description
Quantum Noise (QN) is a phenomenon which gives high contribution to the overall noise in the advanced interferometric Gravitational–Wave detectors. In the previous interferometer generation, the most relevant QN component was dominating in the high frequency region (300 Hz –10 kHz) of the detection band. This component of noise could be corrected by injection of optimal squeezed state [1]. Virgo Scientific Collaboration has already implemented Frequency–Independent Squeezing (FIS) injection to the readout port of Advanced Virgo and reported improvement of the sensitivity curve of around 3 dB [2]. Currently, the Collaboration focuses on the work on the Frequency–Dependent Squeezing (FDS) injection using filter cavity which will reduce QN either in the high and low–frequency range. At the same time, Virgo Squeezing working group is studying a possible alternative way of producing frequency–dependent squeezed states without the filter cavity. The mechanism of FDS without filter cavity, called EPR squeezing, was proposed theoretically by Ma et al. [3] and subsequently demonstrated feasible by scientific group from ANU and Hamburg [4].
At the moment, development facility for the production of squeezed vacuum at EGO/Virgo site is being adapted for the preliminary experiment on the EPR. The experiment represents a first step toward implementation of the new squeezing generation technique. For the purpose of the project, Perugia group is developing various types of photo-detectors and automation software based on Finite State Machines (FSM).
In the presentation, I overview the current state of work on the facility and I summarize in details the tasks related to the development of electronics and software. In particular, I present the engineering of analogue electronics for cavity locking and squeezed state measurement. In the conclusions, I include the near future steps: FSM scheme, noise hunting and lock automation.
References:
1. Caves, Carlton M. “Quantum-Mechanical Noise in an Interferometer.” Physical Review D 23, no. 8 (April 15, 1981): 1693–1708. doi:10.1103/physrevd.23.1693.
2. VIR-0414A-19, TDS report document, J.P. Zendri for the squeezing working group
3. Ma, Yiqiu, Haixing Miao, Belinda Heyun Pang, Matthew Evans, Chunnong Zhao, Jan Harms, Roman Schnabel, and Yanbei Chen. “Proposal for Gravitational-Wave Detection Beyond the Standard Quantum Limit through EPR Entanglement.” Nature Physics 13, no. 8 (May 15, 2017): 776–780. doi:10.1038/nphys4118.
4. Gniesmer, Jan, Mikhail Korobko, Sebastian Steinlecher, and Roman Schnabel. “Frequency-Dependent Squeezed States for Gravitational-Wave Detection through EPR Entanglement.” Quantum Information and Measurement (QIM) V: Quantum Technologies (2019). doi:10.1364/qim.2019.s2b.4.
