Boosting the sensitivity of high frequency gravitational wave detectors by PT-symmetry

TL;DR

This paper proposes a PT-symmetric optomechanical quantum amplifier to significantly enhance high-frequency gravitational wave detector sensitivity, enabling better detection of neutron star merger signals around 3kHz.

Contribution

It introduces a novel PT-symmetric quantum amplification protocol to extend the sensitivity band of gravitational wave detectors at high frequencies.

Findings

Sensitivity improved by one order of magnitude at 3kHz

Detection band significantly broadened in the kilo-Hertz range

Quantum-noise-limited sensitivity and stability analyzed

Abstract

The kilo-Hertz gravitational waves radiated by the neutron star merger remnants carry rich information about the physics of high-density nuclear matter states, and many important astrophysical phenomena such as gamma-ray bursts and black hole formation. Current laser interferometer gravitational wave detectors, such as LIGO, VIRGO, and KAGRA have limited signal response at the kilo-Hertz band, thereby unable to capture these important physical phenomena. This work proposes an alternative protocol for boosting the sensitivity of the gravitational wave detectors at high frequency by implementing an optomechanical quantum amplifier. With the auxiliary quantum amplifier, this design has the feature of Parity-Time (PT) symmetry so that the detection band will be significantly broadened within the kilo-Hertz range. In this work, we carefully analyze the quantum-noise-limited sensitivity and the dynamical stability of this design. Based on our protocol, our result shows that the quantum-noise-limited sensitivity will be improved by one order of magnitude around 3kHz, which indicates the potential of our design for a future search of neutron star merger signals.