Phase-preserving linear amplifiers not simulable by the parametric amplifier

• Main Authors: Chia, A., Hajdušek, M., Nair, Ranjith, Fazio, R., Kwek, L. C., Vedral, V.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Physics; Nonlinear Optics; Open Quantum Systems
• Online Access: https://hdl.handle.net/10356/145780
• Institution: Nanyang Technological University

It is commonly accepted that a parametric amplifier can simulate a phase-preserving linear amplifier regardless of how the latter is realized [C. M. Caves et al., Phys. Rev. A 86, 063802 (2012)]. If true, this reduces all phase-preserving linear amplifiers to a single familiar model. Here we disprove this claim by constructing two counterexamples. A detailed discussion of the physics of our counterexamples is provided. It is shown that a Heisenberg-picture analysis facilitates a microscopic explanation of the physics. This also resolves a question about the nature of amplifier-added noise in degenerate two-photon amplification.