A parametric amplifier is in essence a linear four-port device, which couples and linearly mixes two inputs before amplifying and sending them to two output ports. Here, we show that for quadrature-phase amplitudes, a parametric amplifier can replace beam splitters to play the role of mixer. We apply this idea to a continuous-variable quantum state teleportation scheme in which a parametric amplifier replaces a beam splitter in Bell measurement. We show that this scheme is loss-tolerant in the Bell measurement process and thus demonstrate the advantage of PA over BS in the applications in quantum measurement.
@article{arxiv.2006.08133,
title = {Parametric amplifier for Bell measurement in continuous-variable quantum state teleportation},
author = {Xin Chen and Z. Y. Ou},
journal= {arXiv preprint arXiv:2006.08133},
year = {2020}
}