No Tradeoff between Coherence and Sub-Poissonianity for Heisenberg-Limited Lasers

作者：L. A. Ostrowski, Travis J. Baker, S. N. Saadatmand, Howard M. Wiseman · 发表于：Physical Review Letters · 年份：2023 · DOI：10.1103/physrevlett.130.183602 · 被引用次数：7 · 研究领域：Quantum Mechanics and Applications、Quantum Information and Cryptography、Cold Atom Physics and Bose-Einstein Condensates

The Heisenberg limit to laser coherence C-the number of photons in the maximally populated mode of the laser beam-is the fourth power of the number of excitations inside the laser. We generalize the previous proof of this upper bound scaling by dropping the requirement that the beam photon statistics be Poissonian (i.e., Mandel's Q=0). We then show that the relation between C and sub-Poissonianity (Q<0) is win-win, not a tradeoff. For both regular (non-Markovian) pumping with semiunitary gain (which allows Q→-1), and random (Markovian) pumping with optimized gain, C is maximized when Q is minimized.