Entanglement sensitivity to signal attenuation and amplification

FILIPPOV, Sergey N. and Mário ZIMAN. Entanglement sensitivity to signal attenuation and amplification. Physical Review A. 2014, vol. 90, No 1, p. 1-5. ISSN 1050-2947. Available from: https://dx.doi.org/10.1103/PhysRevA.90.010301.

Basic information

• Original name: Entanglement sensitivity to signal attenuation and amplification
• Authors: FILIPPOV, Sergey N. (643 Russian Federation) and Mário ZIMAN (703 Slovakia, guarantor, belonging to the institution).
• Edition: Physical Review A, 2014, 1050-2947.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10301 Atomic, molecular and chemical physics
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 2.808
• RIV identification code: RIV/00216224:14330/14:00073889
• Organization unit: Faculty of Informatics
• Doi: http://dx.doi.org/10.1103/PhysRevA.90.010301
• UT WoS: 000338649000001
• Keywords in English: quantum information; entanglement; quantum dynamics; quantum optics

Abstract

We analyze general laws of continuous-variable entanglement dynamics during the deterministic attenuation and amplification of the physical signal carrying the entanglement. These processes are inevitably accompanied by noises, so we find fundamental limitations on noise intensities that destroy entanglement of Gaussian and non-Gaussian input states. The phase-insensitive amplification Phi1(x)Phi2(x)...(x)PhiN with the power gain ki>2 (approx 3 dB, i=1,...,N) is shown to destroy entanglement of any N-mode Gaussian state even in the case of quantum-limited performance. In contrast, we demonstrate non-Gaussian states with the energy of a few photons such that their entanglement survives within a wide range of noises beyond quantum-limited performance for any degree of attenuation or gain. We detect entanglement preservation properties of the channel Phi1(x)Phi2, where each mode is deterministically attenuated or amplified. Gaussian states of high energy are shown to be robust to very asymmetric attenuations, whereas non-Gaussian states are at an advantage in the case of symmetric attenuation and general amplification. If Phi1=Phi2, the total noise should not exceed 0.5(1+k2)1/2 to guarantee entanglement preservation.

Links

• GAP202/12/1142, research and development project: Name: Slabé zdroje entanglementu a náhodnosti

Investor: Czech Science Foundation