2008/07/31 by U. Dorner, R. Demkowicz-Dobrzanski, B. J. Smith +4 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.102.040403
published as Phys. Rev. Lett. 102, 040403 (2009) · 4 pages, 4 figures. Replaced with final version
arxiv created 2009/02/06 · arxiv updated 2009/12/01
By using a systematic optimization approach we determine quantum states of light with definite photon number leading to the best possible precision in optical two mode interferometry. Our treatment takes into account the experimentally relevant situation of photon losses. Our results thus reveal the benchmark for precision in optical interferometry. Although this boundary is generally worse than the Heisenberg limit, we show that the obtained precision beats the standard quantum limit thus leading to a significant improvement compared to classical interferometers. We furthermore discuss alternative states and strategies to the optimized states which are easier to generate at the cost of only slightly lower precision.