2016/08/31 by Qian-Kun Gong, Dong Li, Chun-Hua Yuan +4 · 26 citations
Computer Science · Physics and Astronomy · #Gaussian #Heisenberg limit #Interferometry #Phase (matter) #Photon #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum limit #Squeezed coherent state #Vacuum state #quant-ph
paper · pdf · doi:10.1088/1674-1056/26/9/094205
published in Chinese Physics B 26(9), 094205 (IOP Publishing) · 6 pages for the main text and 5 pages for the supplemental material
openalex publication_date 2017/08/01 · openalex created_date 2017/09/15 · arxiv created 2018/06/14 · arxiv updated 2018/06/20 · openalex updated_date 2026/08/05
We theoretically present the quantum Cram'er-Rao bounds (QCRB) of an SU(1,1) interferometer for Gaussian states input with and without the internal photonic losses. The phase shifts in the single arm and in the double arms are studied and the corresponding analytical expressions of quantum Fisher information with Gaussian input states are presented. Different from the traditional Mach-Zehnder interferometer, the QCRB of single arm case is slightly higher or lower than that of double arms case depending on the input states. With a fixed mean photon number and for pure Gaussian state input, the optimal sensitivity is achieved with a squeezed vacuum input in one mode and the vacuum input in the other. We compare the QCRB with the standard quantum limit and Heisenberg limit. In the case of small internal losses the QCRB can beat the standard quantum limit.