We show that the generation of entanglement of two heavily macroscopic mirrors with masses of up to several kilograms are feasible with state of the art techniques of high-precision laser interferometry. The basis of such a demonstration would be a Michelson interferometer with suspended mirrors and simultaneous homodyne detections at both interferometer output ports. We present the connection between the generation of entanglement and the Standard Quantum Limit (SQL) for a free mass. The SQL is a well-known reference limit in operating interferometers for gravitational-wave detection and provides a measure of when macroscopic entanglement can be observed in the presence of realistic decoherence processes.
@article{arxiv.quant-ph/0702258,
title = {Entanglement of macroscopic test masses and the Standard Quantum Limit in laser interferometry},
author = {Helge Mueller-Ebhardt and Henning Rehbein and Roman Schnabel and Karsten Danzmann and Yanbei Chen},
journal= {arXiv preprint arXiv:quant-ph/0702258},
year = {2008}
}